mcs/class/System/System.Net/WebClient.cs

   1 //
   2 // System.Net.WebClient
   3 //
   4 // Authors:
   5 //      Lawrence Pit (loz@cable.a2000.nl)
   6 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   7 //      Atsushi Enomoto (atsushi@ximian.com)
   8 //      Miguel de Icaza (miguel@ximian.com)
   9 //
  10 // Copyright 2003 Ximian, Inc. (http://www.ximian.com)
  11 // Copyright 2006, 2010 Novell, Inc. (http://www.novell.com)
  12 //
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33 //
  34 // Notes on CancelAsync and Async methods:
  35 //
  36 //    WebClient.CancelAsync is implemented by calling Thread.Interrupt
  37 //    in our helper thread.   The various async methods have to cancel
  38 //    any ongoing requests by calling request.Abort () at that point.
  39 //    In a few places (UploadDataCore, UploadValuesCore,
  40 //    UploadFileCore) we catch the ThreadInterruptedException and
  41 //    abort the request there.
  42 //
  43 //    Higher level routines (the async callbacks) also need to catch
  44 //    the exception and raise the OnXXXXCompleted events there with
  45 //    the "canceled" flag set to true.
  46 //
  47 //    In a few other places where these helper routines are not used
  48 //    (OpenReadAsync for example) catching the ThreadAbortException
  49 //    also must abort the request.
  50 //
  51 //    The Async methods currently differ in their implementation from
  52 //    the .NET implementation in that we manually catch any other
  53 //    exceptions and correctly raise the OnXXXXCompleted passing the
  54 //    Exception that caused the problem.   The .NET implementation
  55 //    does not seem to have a mechanism to flag errors that happen
  56 //    during downloads though.    We do this because we still need to
  57 //    catch the exception on these helper threads, or we would
  58 //    otherwise kill the application (on the 2.x profile, uncaught
  59 //    exceptions in threads terminate the application).
  60 //
  61 using System;
  62 using System.Collections.Specialized;
  63 using System.ComponentModel;
  64 using System.IO;
  65 using System.Runtime.InteropServices;
  66 using System.Runtime.Serialization;
  67 using System.Text;
  68 using System.Threading;
  69 using System.Net.Cache;
  70
  71 namespace System.Net
  72 {
  73         [ComVisible(true)]
  74         public class WebClient : Component
  75         {
  76                 static readonly string urlEncodedCType = "application/x-www-form-urlencoded";
  77                 static byte [] hexBytes;
  78                 ICredentials credentials;
  79                 WebHeaderCollection headers;
  80                 WebHeaderCollection responseHeaders;
  81                 Uri baseAddress;
  82                 string baseString;
  83                 NameValueCollection queryString;
  84                 bool is_busy;
  85                 bool async;
  86                 Thread async_thread;
  87                 Encoding encoding = Encoding.Default;
  88                 IWebProxy proxy;
  89                 RequestCachePolicy cache_policy;
  90
  91                 // Constructors
  92                 static WebClient ()
  93                 {
  94                         hexBytes = new byte [16];
  95                         int index = 0;
  96                         for (int i = '0'; i <= '9'; i++, index++)
  97                                 hexBytes [index] = (byte) i;
  98
  99                         for (int i = 'a'; i <= 'f'; i++, index++)
 100                                 hexBytes [index] = (byte) i;
 101                 }
 102
 103                 public WebClient ()
 104                 {
 105                 }
 106
 107                 // Properties
 108
 109                 public string BaseAddress {
 110                         get {
 111                                 if (baseString == null) {
 112                                         if (baseAddress == null)
 113                                                 return string.Empty;
 114                                 }
 115
 116                                 baseString = baseAddress.ToString ();
 117                                 return baseString;
 118                         }
 119
 120                         set {
 121                                 if (value == null || value.Length == 0) {
 122                                         baseAddress = null;
 123                                 } else {
 124                                         baseAddress = new Uri (value);
 125                                 }
 126                         }
 127                 }
 128
 129                 static Exception GetMustImplement ()
 130                 {
 131                         return new NotImplementedException ();
 132                 }
 133
 134                 [MonoTODO ("Value can be set but is currently ignored")]
 135                 public RequestCachePolicy CachePolicy
 136                 {
 137                         get {
 138                                 throw GetMustImplement ();
 139                         }
 140                         set { cache_policy = value; }
 141                 }
 142
 143                 [MonoTODO ("Value can be set but is ignored")]
 144                 public bool UseDefaultCredentials
 145                 {
 146                         get {
 147                                 throw GetMustImplement ();
 148                         }
 149                         set {
 150                                 // This makes no sense in mono
 151                         }
 152                 }
 153
 154                 public ICredentials Credentials {
 155                         get { return credentials; }
 156                         set { credentials = value; }
 157                 }
 158
 159                 public WebHeaderCollection Headers {
 160                         get {
 161                                 if (headers == null)
 162                                         headers = new WebHeaderCollection ();
 163
 164                                 return headers;
 165                         }
 166                         set { headers = value; }
 167                 }
 168
 169                 public NameValueCollection QueryString {
 170                         get {
 171                                 if (queryString == null)
 172                                         queryString = new NameValueCollection ();
 173
 174                                 return queryString;
 175                         }
 176                         set { queryString = value; }
 177                 }
 178
 179                 public WebHeaderCollection ResponseHeaders {
 180                         get { return responseHeaders; }
 181                 }
 182
 183                 public Encoding Encoding {
 184                         get { return encoding; }
 185                         set {
 186                                 if (value == null)
 187                                         throw new ArgumentNullException ("Encoding");
 188                                 encoding = value;
 189                         }
 190                 }
 191
 192                 public IWebProxy Proxy {
 193                         get { return proxy; }
 194                         set { proxy = value; }
 195                 }
 196
 197                 public bool IsBusy {
 198                         get { return is_busy; }
 199                 }
 200                 // Methods
 201
 202                 void CheckBusy ()
 203                 {
 204                         if (IsBusy)
 205                                 throw new NotSupportedException ("WebClient does not support conccurent I/O operations.");
 206                 }
 207
 208                 void SetBusy ()
 209                 {
 210                         lock (this) {
 211                                 CheckBusy ();
 212                                 is_busy = true;
 213                         }
 214                 }
 215
 216                 //   DownloadData
 217
 218                 public byte [] DownloadData (string address)
 219                 {
 220                         if (address == null)
 221                                 throw new ArgumentNullException ("address");
 222
 223                         return DownloadData (CreateUri (address));
 224                 }
 225
 226                 public byte [] DownloadData (Uri address)
 227                 {
 228                         if (address == null)
 229                                 throw new ArgumentNullException ("address");
 230
 231                         try {
 232                                 SetBusy ();
 233                                 async = false;
 234                                 return DownloadDataCore (address, null);
 235                         } finally {
 236                                 is_busy = false;
 237                         }
 238                 }
 239
 240                 byte [] DownloadDataCore (Uri address, object userToken)
 241                 {
 242                         WebRequest request = null;
 243
 244                         try {
 245                                 request = SetupRequest (address);
 246                                 return ReadAll (request, userToken);
 247                         } catch (ThreadInterruptedException){
 248                                 if (request != null)
 249                                         request.Abort ();
 250                                 throw;
 251                         } catch (WebException) {
 252                                 throw;
 253                         } catch (Exception ex) {
 254                                 throw new WebException ("An error occurred " +
 255                                         "performing a WebClient request.", ex);
 256                         }
 257                 }
 258
 259                 //   DownloadFile
 260
 261                 public void DownloadFile (string address, string fileName)
 262                 {
 263                         if (address == null)
 264                                 throw new ArgumentNullException ("address");
 265
 266                         DownloadFile (CreateUri (address), fileName);
 267                 }
 268
 269                 public void DownloadFile (Uri address, string fileName)
 270                 {
 271                         if (address == null)
 272                                 throw new ArgumentNullException ("address");
 273                         if (fileName == null)
 274                                 throw new ArgumentNullException ("fileName");
 275
 276                         try {
 277                                 SetBusy ();
 278                                 async = false;
 279                                 DownloadFileCore (address, fileName, null);
 280                         } catch (WebException) {
 281                                 throw;
 282                         } catch (Exception ex) {
 283                                 throw new WebException ("An error occurred " +
 284                                         "performing a WebClient request.", ex);
 285                         } finally {
 286                                 is_busy = false;
 287                         }
 288                 }
 289
 290                 void DownloadFileCore (Uri address, string fileName, object userToken)
 291                 {
 292                         WebRequest request = null;
 293
 294                         using (FileStream f = new FileStream (fileName, FileMode.Create)) {
 295                                 try {
 296                                         request = SetupRequest (address);
 297                                         WebResponse response = GetWebResponse (request);
 298                                         Stream st = response.GetResponseStream ();
 299
 300                                         int cLength = (int) response.ContentLength;
 301                                         int length = (cLength <= -1 || cLength > 32*1024) ? 32*1024 : cLength;
 302                                         byte [] buffer = new byte [length];
 303
 304                                         int nread = 0;
 305                                         long notify_total = 0;
 306                                         while ((nread = st.Read (buffer, 0, length)) != 0){
 307                                                 if (async){
 308                                                         notify_total += nread;
 309                                                         OnDownloadProgressChanged (
 310                                                                 new DownloadProgressChangedEventArgs (notify_total, response.ContentLength, userToken));
 311
 312                                                 }
 313                                                 f.Write (buffer, 0, nread);
 314                                         }
 315                                 } catch (ThreadInterruptedException){
 316                                         if (request != null)
 317                                                 request.Abort ();
 318                                         throw;
 319                                 }
 320                         }
 321                 }
 322
 323                 //   OpenRead
 324
 325                 public Stream OpenRead (string address)
 326                 {
 327                         if (address == null)
 328                                 throw new ArgumentNullException ("address");
 329                         return OpenRead (CreateUri (address));
 330                 }
 331
 332                 public Stream OpenRead (Uri address)
 333                 {
 334                         if (address == null)
 335                                 throw new ArgumentNullException ("address");
 336
 337                         WebRequest request = null;
 338                         try {
 339                                 SetBusy ();
 340                                 async = false;
 341                                 request = SetupRequest (address);
 342                                 WebResponse response = GetWebResponse (request);
 343                                 return response.GetResponseStream ();
 344                         } catch (WebException) {
 345                                 throw;
 346                         } catch (Exception ex) {
 347                                 throw new WebException ("An error occurred " +
 348                                         "performing a WebClient request.", ex);
 349                         } finally {
 350                                 is_busy = false;
 351                         }
 352                 }
 353
 354                 //   OpenWrite
 355
 356                 public Stream OpenWrite (string address)
 357                 {
 358                         if (address == null)
 359                                 throw new ArgumentNullException ("address");
 360
 361                         return OpenWrite (CreateUri (address));
 362                 }
 363
 364                 public Stream OpenWrite (string address, string method)
 365                 {
 366                         if (address == null)
 367                                 throw new ArgumentNullException ("address");
 368
 369                         return OpenWrite (CreateUri (address), method);
 370                 }
 371
 372                 public Stream OpenWrite (Uri address)
 373                 {
 374                         return OpenWrite (address, (string) null);
 375                 }
 376
 377                 public Stream OpenWrite (Uri address, string method)
 378                 {
 379                         if (address == null)
 380                                 throw new ArgumentNullException ("address");
 381
 382                         try {
 383                                 SetBusy ();
 384                                 async = false;
 385                                 WebRequest request = SetupRequest (address, method, true);
 386                                 return request.GetRequestStream ();
 387                         } catch (WebException) {
 388                                 throw;
 389                         } catch (Exception ex) {
 390                                 throw new WebException ("An error occurred " +
 391                                         "performing a WebClient request.", ex);
 392                         } finally {
 393                                 is_busy = false;
 394                         }
 395                 }
 396
 397                 private string DetermineMethod (Uri address, string method, bool is_upload)
 398                 {
 399                         if (method != null)
 400                                 return method;
 401
 402                         if (address.Scheme == Uri.UriSchemeFtp)
 403                                 return (is_upload) ? "STOR" : "RETR";
 404
 405                         return (is_upload) ? "POST" : "GET";
 406                 }
 407
 408                 //   UploadData
 409
 410                 public byte [] UploadData (string address, byte [] data)
 411                 {
 412                         if (address == null)
 413                                 throw new ArgumentNullException ("address");
 414
 415                         return UploadData (CreateUri (address), data);
 416                 }
 417
 418                 public byte [] UploadData (string address, string method, byte [] data)
 419                 {
 420                         if (address == null)
 421                                 throw new ArgumentNullException ("address");
 422
 423                         return UploadData (CreateUri (address), method, data);
 424                 }
 425
 426                 public byte [] UploadData (Uri address, byte [] data)
 427                 {
 428                         return UploadData (address, (string) null, data);
 429                 }
 430
 431                 public byte [] UploadData (Uri address, string method, byte [] data)
 432                 {
 433                         if (address == null)
 434                                 throw new ArgumentNullException ("address");
 435                         if (data == null)
 436                                 throw new ArgumentNullException ("data");
 437
 438                         try {
 439                                 SetBusy ();
 440                                 async = false;
 441                                 return UploadDataCore (address, method, data, null);
 442                         } catch (WebException) {
 443                                 throw;
 444                         } catch (Exception ex) {
 445                                 throw new WebException ("An error occurred " +
 446                                         "performing a WebClient request.", ex);
 447                         } finally {
 448                                 is_busy = false;
 449                         }
 450                 }
 451
 452                 byte [] UploadDataCore (Uri address, string method, byte [] data, object userToken)
 453                 {
 454                         WebRequest request = SetupRequest (address, method, true);
 455                         try {
 456                                 int contentLength = data.Length;
 457                                 request.ContentLength = contentLength;
 458                                 using (Stream stream = request.GetRequestStream ()) {
 459                                         stream.Write (data, 0, contentLength);
 460                                 }
 461
 462                                 return ReadAll (request, userToken);
 463                         } catch (ThreadInterruptedException){
 464                                 if (request != null)
 465                                         request.Abort ();
 466                                 throw;
 467                         }
 468                 }
 469
 470                 //   UploadFile
 471
 472                 public byte [] UploadFile (string address, string fileName)
 473                 {
 474                         if (address == null)
 475                                 throw new ArgumentNullException ("address");
 476
 477                         return UploadFile (CreateUri (address), fileName);
 478                 }
 479
 480                 public byte [] UploadFile (Uri address, string fileName)
 481                 {
 482                         return UploadFile (address, (string) null, fileName);
 483                 }
 484
 485                 public byte [] UploadFile (string address, string method, string fileName)
 486                 {
 487                         return UploadFile (CreateUri (address), method, fileName);
 488                 }
 489
 490                 public byte [] UploadFile (Uri address, string method, string fileName)
 491                 {
 492                         if (address == null)
 493                                 throw new ArgumentNullException ("address");
 494                         if (fileName == null)
 495                                 throw new ArgumentNullException ("fileName");
 496
 497                         try {
 498                                 SetBusy ();
 499                                 async = false;
 500                                 return UploadFileCore (address, method, fileName, null);
 501                         } catch (WebException) {
 502                                 throw;
 503                         } catch (Exception ex) {
 504                                 throw new WebException ("An error occurred " +
 505                                         "performing a WebClient request.", ex);
 506                         } finally {
 507                                 is_busy = false;
 508                         }
 509                 }
 510
 511                 byte [] UploadFileCore (Uri address, string method, string fileName, object userToken)
 512                 {
 513                         string fileCType = Headers ["Content-Type"];
 514                         if (fileCType != null) {
 515                                 string lower = fileCType.ToLower ();
 516                                 if (lower.StartsWith ("multipart/"))
 517                                         throw new WebException ("Content-Type cannot be set to a multipart" +
 518                                                                 " type for this request.");
 519                         } else {
 520                                 fileCType = "application/octet-stream";
 521                         }
 522
 523                         string boundary = "------------" + DateTime.Now.Ticks.ToString ("x");
 524                         Headers ["Content-Type"] = String.Format ("multipart/form-data; boundary={0}", boundary);
 525                         Stream reqStream = null;
 526                         Stream fStream = null;
 527                         byte [] resultBytes = null;
 528
 529                         fileName = Path.GetFullPath (fileName);
 530
 531                         WebRequest request = null;
 532                         try {
 533                                 fStream = File.OpenRead (fileName);
 534                                 request = SetupRequest (address, method, true);
 535                                 reqStream = request.GetRequestStream ();
 536                                 byte [] bytes_boundary = Encoding.ASCII.GetBytes (boundary);
 537                                 reqStream.WriteByte ((byte) '-');
 538                                 reqStream.WriteByte ((byte) '-');
 539                                 reqStream.Write (bytes_boundary, 0, bytes_boundary.Length);
 540                                 reqStream.WriteByte ((byte) '\r');
 541                                 reqStream.WriteByte ((byte) '\n');
 542                                 string partHeaders = String.Format ("Content-Disposition: form-data; " +
 543                                                                     "name=\"file\"; filename=\"{0}\"\r\n" +
 544                                                                     "Content-Type: {1}\r\n\r\n",
 545                                                                     Path.GetFileName (fileName), fileCType);
 546
 547                                 byte [] partHeadersBytes = Encoding.UTF8.GetBytes (partHeaders);
 548                                 reqStream.Write (partHeadersBytes, 0, partHeadersBytes.Length);
 549                                 int nread;
 550                                 byte [] buffer = new byte [4096];
 551                                 while ((nread = fStream.Read (buffer, 0, 4096)) != 0)
 552                                         reqStream.Write (buffer, 0, nread);
 553
 554                                 reqStream.WriteByte ((byte) '\r');
 555                                 reqStream.WriteByte ((byte) '\n');
 556                                 reqStream.WriteByte ((byte) '-');
 557                                 reqStream.WriteByte ((byte) '-');
 558                                 reqStream.Write (bytes_boundary, 0, bytes_boundary.Length);
 559                                 reqStream.WriteByte ((byte) '-');
 560                                 reqStream.WriteByte ((byte) '-');
 561                                 reqStream.WriteByte ((byte) '\r');
 562                                 reqStream.WriteByte ((byte) '\n');
 563                                 reqStream.Close ();
 564                                 reqStream = null;
 565                                 resultBytes = ReadAll (request, userToken);
 566                         } catch (ThreadInterruptedException){
 567                                 if (request != null)
 568                                         request.Abort ();
 569                                 throw;
 570                         } finally {
 571                                 if (fStream != null)
 572                                         fStream.Close ();
 573
 574                                 if (reqStream != null)
 575                                         reqStream.Close ();
 576                         }
 577
 578                         return resultBytes;
 579                 }
 580
 581                 public byte[] UploadValues (string address, NameValueCollection data)
 582                 {
 583                         if (address == null)
 584                                 throw new ArgumentNullException ("address");
 585
 586                         return UploadValues (CreateUri (address), data);
 587                 }
 588
 589                 public byte[] UploadValues (string address, string method, NameValueCollection data)
 590                 {
 591                         if (address == null)
 592                                 throw new ArgumentNullException ("address");
 593                         return UploadValues (CreateUri (address), method, data);
 594                 }
 595
 596                 public byte[] UploadValues (Uri address, NameValueCollection data)
 597                 {
 598                         return UploadValues (address, (string) null, data);
 599                 }
 600
 601                 public byte[] UploadValues (Uri address, string method, NameValueCollection data)
 602                 {
 603                         if (address == null)
 604                                 throw new ArgumentNullException ("address");
 605                         if (data == null)
 606                                 throw new ArgumentNullException ("data");
 607
 608                         try {
 609                                 SetBusy ();
 610                                 async = false;
 611                                 return UploadValuesCore (address, method, data, null);
 612                         } catch (WebException) {
 613                                 throw;
 614                         } catch (Exception ex) {
 615                                 throw new WebException ("An error occurred " +
 616                                         "performing a WebClient request.", ex);
 617                         } finally {
 618                                 is_busy = false;
 619                         }
 620                 }
 621
 622                 byte[] UploadValuesCore (Uri uri, string method, NameValueCollection data, object userToken)
 623                 {
 624                         string cType = Headers ["Content-Type"];
 625                         if (cType != null && String.Compare (cType, urlEncodedCType, true) != 0)
 626                                 throw new WebException ("Content-Type header cannot be changed from its default " +
 627                                                         "value for this request.");
 628
 629                         Headers ["Content-Type"] = urlEncodedCType;
 630                         WebRequest request = SetupRequest (uri, method, true);
 631                         try {
 632                                 MemoryStream tmpStream = new MemoryStream ();
 633                                 foreach (string key in data) {
 634                                         byte [] bytes = Encoding.UTF8.GetBytes (key);
 635                                         UrlEncodeAndWrite (tmpStream, bytes);
 636                                         tmpStream.WriteByte ((byte) '=');
 637                                         bytes = Encoding.UTF8.GetBytes (data [key]);
 638                                         UrlEncodeAndWrite (tmpStream, bytes);
 639                                         tmpStream.WriteByte ((byte) '&');
 640                                 }
 641
 642                                 int length = (int) tmpStream.Length;
 643                                 if (length > 0)
 644                                         tmpStream.SetLength (--length); // remove trailing '&'
 645
 646                                 byte [] buf = tmpStream.GetBuffer ();
 647                                 request.ContentLength = length;
 648                                 using (Stream rqStream = request.GetRequestStream ()) {
 649                                         rqStream.Write (buf, 0, length);
 650                                 }
 651                                 tmpStream.Close ();
 652
 653                                 return ReadAll (request, userToken);
 654                         } catch (ThreadInterruptedException) {
 655                                 request.Abort ();
 656                                 throw;
 657                         }
 658                 }
 659
 660                 public string DownloadString (string address)
 661                 {
 662                         if (address == null)
 663                                 throw new ArgumentNullException ("address");
 664
 665                         return encoding.GetString (DownloadData (CreateUri (address)));
 666                 }
 667
 668                 public string DownloadString (Uri address)
 669                 {
 670                         if (address == null)
 671                                 throw new ArgumentNullException ("address");
 672
 673                         return encoding.GetString (DownloadData (CreateUri (address)));
 674                 }
 675
 676                 public string UploadString (string address, string data)
 677                 {
 678                         if (address == null)
 679                                 throw new ArgumentNullException ("address");
 680                         if (data == null)
 681                                 throw new ArgumentNullException ("data");
 682
 683                         byte [] resp = UploadData (address, encoding.GetBytes (data));
 684                         return encoding.GetString (resp);
 685                 }
 686
 687                 public string UploadString (string address, string method, string data)
 688                 {
 689                         if (address == null)
 690                                 throw new ArgumentNullException ("address");
 691                         if (data == null)
 692                                 throw new ArgumentNullException ("data");
 693
 694                         byte [] resp = UploadData (address, method, encoding.GetBytes (data));
 695                         return encoding.GetString (resp);
 696                 }
 697
 698                 public string UploadString (Uri address, string data)
 699                 {
 700                         if (address == null)
 701                                 throw new ArgumentNullException ("address");
 702                         if (data == null)
 703                                 throw new ArgumentNullException ("data");
 704
 705                         byte [] resp = UploadData (address, encoding.GetBytes (data));
 706                         return encoding.GetString (resp);
 707                 }
 708
 709                 public string UploadString (Uri address, string method, string data)
 710                 {
 711                         if (address == null)
 712                                 throw new ArgumentNullException ("address");
 713                         if (data == null)
 714                                 throw new ArgumentNullException ("data");
 715
 716                         byte [] resp = UploadData (address, method, encoding.GetBytes (data));
 717                         return encoding.GetString (resp);
 718                 }
 719
 720                 public event DownloadDataCompletedEventHandler DownloadDataCompleted;
 721                 public event AsyncCompletedEventHandler DownloadFileCompleted;
 722                 public event DownloadProgressChangedEventHandler DownloadProgressChanged;
 723                 public event DownloadStringCompletedEventHandler DownloadStringCompleted;
 724                 public event OpenReadCompletedEventHandler OpenReadCompleted;
 725                 public event OpenWriteCompletedEventHandler OpenWriteCompleted;
 726                 public event UploadDataCompletedEventHandler UploadDataCompleted;
 727                 public event UploadFileCompletedEventHandler UploadFileCompleted;
 728                 public event UploadProgressChangedEventHandler UploadProgressChanged;
 729                 public event UploadStringCompletedEventHandler UploadStringCompleted;
 730                 public event UploadValuesCompletedEventHandler UploadValuesCompleted;
 731
 732                 Uri CreateUri (string address)
 733                 {
 734                         Uri uri;
 735                         try {
 736                                 if (baseAddress == null)
 737                                         uri = new Uri (address);
 738                                 else
 739                                         uri = new Uri (baseAddress, address);
 740                                 return CreateUri (uri);
 741                         } catch {
 742                         }
 743                         return new Uri (Path.GetFullPath (address));
 744                 }
 745
 746                 Uri CreateUri (Uri address)
 747                 {
 748                         Uri result = address;
 749                         if (baseAddress != null && !result.IsAbsoluteUri) {
 750                                 try {
 751                                         result = new Uri (baseAddress, result.OriginalString);
 752                                 } catch {
 753                                         return result; // Not much we can do here.
 754                                 }
 755                         }
 756
 757                         string query = result.Query;
 758                         if (String.IsNullOrEmpty (query))
 759                                 query = GetQueryString (true);
 760                         UriBuilder builder = new UriBuilder (address);
 761                         if (!String.IsNullOrEmpty (query))
 762                                 builder.Query = query.Substring (1);
 763                         return builder.Uri;
 764                 }
 765
 766                 string GetQueryString (bool add_qmark)
 767                 {
 768                         if (queryString == null || queryString.Count == 0)
 769                                 return null;
 770
 771                         StringBuilder sb = new StringBuilder ();
 772                         if (add_qmark)
 773                                 sb.Append ('?');
 774
 775                         foreach (string key in queryString)
 776                                 sb.AppendFormat ("{0}={1}&", key, UrlEncode (queryString [key]));
 777
 778                         if (sb.Length != 0)
 779                                 sb.Length--; // removes last '&' or the '?' if empty.
 780
 781                         if (sb.Length == 0)
 782                                 return null;
 783
 784                         return sb.ToString ();
 785                 }
 786
 787                 WebRequest SetupRequest (Uri uri)
 788                 {
 789                         WebRequest request = GetWebRequest (uri);
 790                         if (Proxy != null)
 791                                 request.Proxy = Proxy;
 792                         request.Credentials = credentials;
 793
 794                         // Special headers. These are properties of HttpWebRequest.
 795                         // What do we do with other requests differnt from HttpWebRequest?
 796                         if (headers != null && headers.Count != 0 && (request is HttpWebRequest)) {
 797                                 HttpWebRequest req = (HttpWebRequest) request;
 798                                 string expect = headers ["Expect"];
 799                                 string contentType = headers ["Content-Type"];
 800                                 string accept = headers ["Accept"];
 801                                 string connection = headers ["Connection"];
 802                                 string userAgent = headers ["User-Agent"];
 803                                 string referer = headers ["Referer"];
 804                                 headers.RemoveInternal ("Expect");
 805                                 headers.RemoveInternal ("Content-Type");
 806                                 headers.RemoveInternal ("Accept");
 807                                 headers.RemoveInternal ("Connection");
 808                                 headers.RemoveInternal ("Referer");
 809                                 headers.RemoveInternal ("User-Agent");
 810                                 request.Headers = headers;
 811
 812                                 if (expect != null && expect.Length > 0)
 813                                         req.Expect = expect;
 814
 815                                 if (accept != null && accept.Length > 0)
 816                                         req.Accept = accept;
 817
 818                                 if (contentType != null && contentType.Length > 0)
 819                                         req.ContentType = contentType;
 820
 821                                 if (connection != null && connection.Length > 0)
 822                                         req.Connection = connection;
 823
 824                                 if (userAgent != null && userAgent.Length > 0)
 825                                         req.UserAgent = userAgent;
 826
 827                                 if (referer != null && referer.Length > 0)
 828                                         req.Referer = referer;
 829                         }
 830
 831                         responseHeaders = null;
 832                         return request;
 833                 }
 834
 835                 WebRequest SetupRequest (Uri uri, string method, bool is_upload)
 836                 {
 837                         WebRequest request = SetupRequest (uri);
 838                         request.Method = DetermineMethod (uri, method, is_upload);
 839                         return request;
 840                 }
 841
 842                 byte [] ReadAll (WebRequest request, object userToken)
 843                 {
 844                         WebResponse response = GetWebResponse (request);
 845                         Stream stream = response.GetResponseStream ();
 846                         int length = (int) response.ContentLength;
 847                         HttpWebRequest wreq = request as HttpWebRequest;
 848
 849                         if (length > -1 && wreq != null && (int) wreq.AutomaticDecompression != 0) {
 850                                 string content_encoding = ((HttpWebResponse) response).ContentEncoding;
 851                                 if (((content_encoding == "gzip" && (wreq.AutomaticDecompression & DecompressionMethods.GZip) != 0)) ||
 852                                         ((content_encoding == "deflate" && (wreq.AutomaticDecompression & DecompressionMethods.Deflate) != 0)))
 853                                         length = -1;
 854                         }
 855
 856                         MemoryStream ms = null;
 857                         bool nolength = (length == -1);
 858                         int size = ((nolength) ? 8192 : length);
 859                         if (nolength)
 860                                 ms = new MemoryStream ();
 861
 862 //                      long total = 0;
 863                         int nread = 0;
 864                         int offset = 0;
 865                         byte [] buffer = new byte [size];
 866                         while ((nread = stream.Read (buffer, offset, size)) != 0) {
 867                                 if (nolength) {
 868                                         ms.Write (buffer, 0, nread);
 869                                 } else {
 870                                         offset += nread;
 871                                         size -= nread;
 872                                 }
 873                                 if (async){
 874 //                                      total += nread;
 875                                         OnDownloadProgressChanged (new DownloadProgressChangedEventArgs (nread, length, userToken));
 876                                 }
 877                         }
 878
 879                         if (nolength)
 880                                 return ms.ToArray ();
 881
 882                         return buffer;
 883                 }
 884
 885                 string UrlEncode (string str)
 886                 {
 887                         StringBuilder result = new StringBuilder ();
 888
 889                         int len = str.Length;
 890                         for (int i = 0; i < len; i++) {
 891                                 char c = str [i];
 892                                 if (c == ' ')
 893                                         result.Append ('+');
 894                                 else if ((c < '0' && c != '-' && c != '.') ||
 895                                          (c < 'A' && c > '9') ||
 896                                          (c > 'Z' && c < 'a' && c != '_') ||
 897                                          (c > 'z')) {
 898                                         result.Append ('%');
 899                                         int idx = ((int) c) >> 4;
 900                                         result.Append ((char) hexBytes [idx]);
 901                                         idx = ((int) c) & 0x0F;
 902                                         result.Append ((char) hexBytes [idx]);
 903                                 } else {
 904                                         result.Append (c);
 905                                 }
 906                         }
 907
 908                         return result.ToString ();
 909                 }
 910
 911                 static void UrlEncodeAndWrite (Stream stream, byte [] bytes)
 912                 {
 913                         if (bytes == null)
 914                                 return;
 915
 916                         int len = bytes.Length;
 917                         if (len == 0)
 918                                 return;
 919
 920                         for (int i = 0; i < len; i++) {
 921                                 char c = (char) bytes [i];
 922                                 if (c == ' ')
 923                                         stream.WriteByte ((byte) '+');
 924                                 else if ((c < '0' && c != '-' && c != '.') ||
 925                                          (c < 'A' && c > '9') ||
 926                                          (c > 'Z' && c < 'a' && c != '_') ||
 927                                          (c > 'z')) {
 928                                         stream.WriteByte ((byte) '%');
 929                                         int idx = ((int) c) >> 4;
 930                                         stream.WriteByte (hexBytes [idx]);
 931                                         idx = ((int) c) & 0x0F;
 932                                         stream.WriteByte (hexBytes [idx]);
 933                                 } else {
 934                                         stream.WriteByte ((byte) c);
 935                                 }
 936                         }
 937                 }
 938
 939                 public void CancelAsync ()
 940                 {
 941                         lock (this){
 942                                 if (async_thread == null)
 943                                         return;
 944
 945                                 //
 946                                 // We first flag things as done, in case the Interrupt hangs
 947                                 // or the thread decides to hang in some other way inside the
 948                                 // event handlers, or if we are stuck somewhere else.  This
 949                                 // ensures that the WebClient object is reusable immediately
 950                                 //
 951                                 Thread t = async_thread;
 952                                 CompleteAsync ();
 953                                 t.Interrupt ();
 954                         }
 955                 }
 956
 957                 void CompleteAsync ()
 958                 {
 959                         lock (this){
 960                                 is_busy = false;
 961                                 async_thread = null;
 962                         }
 963                 }
 964
 965                 //    DownloadDataAsync
 966
 967                 public void DownloadDataAsync (Uri address)
 968                 {
 969                         DownloadDataAsync (address, null);
 970                 }
 971
 972                 public void DownloadDataAsync (Uri address, object userToken)
 973                 {
 974                         if (address == null)
 975                                 throw new ArgumentNullException ("address");
 976
 977                         lock (this) {
 978                                 SetBusy ();
 979                                 async = true;
 980
 981                                 async_thread = new Thread (delegate (object state) {
 982                                         object [] args = (object []) state;
 983                                         try {
 984                                                 byte [] data = DownloadDataCore ((Uri) args [0], args [1]);
 985                                                 OnDownloadDataCompleted (
 986                                                         new DownloadDataCompletedEventArgs (data, null, false, args [1]));
 987                                         } catch (ThreadInterruptedException){
 988                                                 OnDownloadDataCompleted (
 989                                                         new DownloadDataCompletedEventArgs (null, null, true, args [1]));
 990                                                 throw;
 991                                         } catch (Exception e){
 992                                                 OnDownloadDataCompleted (
 993                                                         new DownloadDataCompletedEventArgs (null, e, false, args [1]));
 994                                         }
 995                                 });
 996                                 object [] cb_args = new object [] {address, userToken};
 997                                 async_thread.Start (cb_args);
 998                         }
 999                 }
1000
1001                 //    DownloadFileAsync
1002
1003                 public void DownloadFileAsync (Uri address, string fileName)
1004                 {
1005                         DownloadFileAsync (address, fileName, null);
1006                 }
1007
1008                 public void DownloadFileAsync (Uri address, string fileName, object userToken)
1009                 {
1010                         if (address == null)
1011                                 throw new ArgumentNullException ("address");
1012                         if (fileName == null)
1013                                 throw new ArgumentNullException ("fileName");
1014
1015                         lock (this) {
1016                                 SetBusy ();
1017                                 async = true;
1018
1019                                 async_thread = new Thread (delegate (object state) {
1020                                         object [] args = (object []) state;
1021                                         try {
1022                                                 DownloadFileCore ((Uri) args [0], (string) args [1], args [2]);
1023                                                 OnDownloadFileCompleted (
1024                                                         new AsyncCompletedEventArgs (null, false, args [2]));
1025                                         } catch (ThreadInterruptedException){
1026                                                 OnDownloadFileCompleted (
1027                                                         new AsyncCompletedEventArgs (null, true, args [2]));
1028                                         } catch (Exception e){
1029                                                 OnDownloadFileCompleted (
1030                                                         new AsyncCompletedEventArgs (e, false, args [2]));
1031                                         }});
1032                                 object [] cb_args = new object [] {address, fileName, userToken};
1033                                 async_thread.Start (cb_args);
1034                         }
1035                 }
1036
1037                 //    DownloadStringAsync
1038
1039                 public void DownloadStringAsync (Uri address)
1040                 {
1041                         DownloadStringAsync (address, null);
1042                 }
1043
1044                 public void DownloadStringAsync (Uri address, object userToken)
1045                 {
1046                         if (address == null)
1047                                 throw new ArgumentNullException ("address");
1048
1049                         lock (this) {
1050                                 SetBusy ();
1051                                 async = true;
1052
1053                                 async_thread = new Thread (delegate (object state) {
1054                                         object [] args = (object []) state;
1055                                         try {
1056                                                 string data = encoding.GetString (DownloadDataCore ((Uri) args [0], args [1]));
1057                                                 OnDownloadStringCompleted (
1058                                                         new DownloadStringCompletedEventArgs (data, null, false, args [1]));
1059                                         } catch (ThreadInterruptedException){
1060                                                 OnDownloadStringCompleted (
1061                                                         new DownloadStringCompletedEventArgs (null, null, true, args [1]));
1062                                         } catch (Exception e){
1063                                                 OnDownloadStringCompleted (
1064                                                         new DownloadStringCompletedEventArgs (null, e, false, args [1]));
1065                                         }});
1066                                 object [] cb_args = new object [] {address, userToken};
1067                                 async_thread.Start (cb_args);
1068                         }
1069                 }
1070
1071                 //    OpenReadAsync
1072
1073                 public void OpenReadAsync (Uri address)
1074                 {
1075                         OpenReadAsync (address, null);
1076                 }
1077
1078                 public void OpenReadAsync (Uri address, object userToken)
1079                 {
1080                         if (address == null)
1081                                 throw new ArgumentNullException ("address");
1082
1083                         lock (this) {
1084                                 SetBusy ();
1085                                 async = true;
1086
1087                                 async_thread = new Thread (delegate (object state) {
1088                                         object [] args = (object []) state;
1089                                         WebRequest request = null;
1090                                         try {
1091                                                 request = SetupRequest ((Uri) args [0]);
1092                                                 WebResponse response = GetWebResponse (request);
1093                                                 Stream stream = response.GetResponseStream ();
1094                                                 OnOpenReadCompleted (
1095                                                         new OpenReadCompletedEventArgs (stream, null, false, args [1]));
1096                                         } catch (ThreadInterruptedException){
1097                                                 if (request != null)
1098                                                         request.Abort ();
1099
1100                                                 OnOpenReadCompleted (new OpenReadCompletedEventArgs (null, null, true, args [1]));
1101                                         } catch (Exception e){
1102                                                 OnOpenReadCompleted (new OpenReadCompletedEventArgs (null, e, false, args [1]));
1103                                         } });
1104                                 object [] cb_args = new object [] {address, userToken};
1105                                 async_thread.Start (cb_args);
1106                         }
1107                 }
1108
1109                 //    OpenWriteAsync
1110
1111                 public void OpenWriteAsync (Uri address)
1112                 {
1113                         OpenWriteAsync (address, null);
1114                 }
1115
1116                 public void OpenWriteAsync (Uri address, string method)
1117                 {
1118                         OpenWriteAsync (address, method, null);
1119                 }
1120
1121                 public void OpenWriteAsync (Uri address, string method, object userToken)
1122                 {
1123                         if (address == null)
1124                                 throw new ArgumentNullException ("address");
1125
1126                         lock (this) {
1127                                 SetBusy ();
1128                                 async = true;
1129
1130                                 async_thread = new Thread (delegate (object state) {
1131                                         object [] args = (object []) state;
1132                                         WebRequest request = null;
1133                                         try {
1134                                                 request = SetupRequest ((Uri) args [0], (string) args [1], true);
1135                                                 Stream stream = request.GetRequestStream ();
1136                                                 OnOpenWriteCompleted (
1137                                                         new OpenWriteCompletedEventArgs (stream, null, false, args [2]));
1138                                         } catch (ThreadInterruptedException){
1139                                                 if (request != null)
1140                                                         request.Abort ();
1141                                                 OnOpenWriteCompleted (
1142                                                         new OpenWriteCompletedEventArgs (null, null, true, args [2]));
1143                                         } catch (Exception e){
1144                                                 OnOpenWriteCompleted (
1145                                                         new OpenWriteCompletedEventArgs (null, e, false, args [2]));
1146                                         }});
1147                                 object [] cb_args = new object [] {address, method, userToken};
1148                                 async_thread.Start (cb_args);
1149                         }
1150                 }
1151
1152                 //    UploadDataAsync
1153
1154                 public void UploadDataAsync (Uri address, byte [] data)
1155                 {
1156                         UploadDataAsync (address, null, data);
1157                 }
1158
1159                 public void UploadDataAsync (Uri address, string method, byte [] data)
1160                 {
1161                         UploadDataAsync (address, method, data, null);
1162                 }
1163
1164                 public void UploadDataAsync (Uri address, string method, byte [] data, object userToken)
1165                 {
1166                         if (address == null)
1167                                 throw new ArgumentNullException ("address");
1168                         if (data == null)
1169                                 throw new ArgumentNullException ("data");
1170
1171                         lock (this) {
1172                                 SetBusy ();
1173                                 async = true;
1174
1175                                 async_thread = new Thread (delegate (object state) {
1176                                         object [] args = (object []) state;
1177                                         byte [] data2;
1178
1179                                         try {
1180                                                 data2 = UploadDataCore ((Uri) args [0], (string) args [1], (byte []) args [2], args [3]);
1181
1182                                                 OnUploadDataCompleted (
1183                                                         new UploadDataCompletedEventArgs (data2, null, false, args [3]));
1184                                         } catch (ThreadInterruptedException){
1185                                                 OnUploadDataCompleted (
1186                                                         new UploadDataCompletedEventArgs (null, null, true, args [3]));
1187                                         } catch (Exception e){
1188                                                 OnUploadDataCompleted (
1189                                                         new UploadDataCompletedEventArgs (null, e, false, args [3]));
1190                                         }});
1191                                 object [] cb_args = new object [] {address, method, data,  userToken};
1192                                 async_thread.Start (cb_args);
1193                         }
1194                 }
1195
1196                 //    UploadFileAsync
1197
1198                 public void UploadFileAsync (Uri address, string fileName)
1199                 {
1200                         UploadFileAsync (address, null, fileName);
1201                 }
1202
1203                 public void UploadFileAsync (Uri address, string method, string fileName)
1204                 {
1205                         UploadFileAsync (address, method, fileName, null);
1206                 }
1207
1208                 public void UploadFileAsync (Uri address, string method, string fileName, object userToken)
1209                 {
1210                         if (address == null)
1211                                 throw new ArgumentNullException ("address");
1212                         if (fileName == null)
1213                                 throw new ArgumentNullException ("fileName");
1214
1215                         lock (this) {
1216                                 SetBusy ();
1217                                 async = true;
1218
1219                                 async_thread = new Thread (delegate (object state) {
1220                                         object [] args = (object []) state;
1221                                         byte [] data;
1222
1223                                         try {
1224                                                 data = UploadFileCore ((Uri) args [0], (string) args [1], (string) args [2], args [3]);
1225                                                 OnUploadFileCompleted (
1226                                                         new UploadFileCompletedEventArgs (data, null, false, args [3]));
1227                                         } catch (ThreadInterruptedException){
1228                                                 OnUploadFileCompleted (
1229                                                         new UploadFileCompletedEventArgs (null, null, true, args [3]));
1230                                         } catch (Exception e){
1231                                                 OnUploadFileCompleted (
1232                                                         new UploadFileCompletedEventArgs (null, e, false, args [3]));
1233                                         }});
1234                                 object [] cb_args = new object [] {address, method, fileName,  userToken};
1235                                 async_thread.Start (cb_args);
1236                         }
1237                 }
1238
1239                 //    UploadStringAsync
1240
1241                 public void UploadStringAsync (Uri address, string data)
1242                 {
1243                         UploadStringAsync (address, null, data);
1244                 }
1245
1246                 public void UploadStringAsync (Uri address, string method, string data)
1247                 {
1248                         UploadStringAsync (address, method, data, null);
1249                 }
1250
1251                 public void UploadStringAsync (Uri address, string method, string data, object userToken)
1252                 {
1253                         if (address == null)
1254                                 throw new ArgumentNullException ("address");
1255                         if (data == null)
1256                                 throw new ArgumentNullException ("data");
1257
1258                         lock (this) {
1259                                 CheckBusy ();
1260                                 async = true;
1261
1262                                 async_thread = new Thread (delegate (object state) {
1263                                         object [] args = (object []) state;
1264
1265                                         try {
1266                                                 string data2 = UploadString ((Uri) args [0], (string) args [1], (string) args [2]);
1267                                                 OnUploadStringCompleted (
1268                                                         new UploadStringCompletedEventArgs (data2, null, false, args [3]));
1269                                         } catch (ThreadInterruptedException){
1270                                                 OnUploadStringCompleted (
1271                                                         new UploadStringCompletedEventArgs (null, null, true, args [3]));
1272                                         } catch (Exception e){
1273                                                 OnUploadStringCompleted (
1274                                                         new UploadStringCompletedEventArgs (null, e, false, args [3]));
1275                                         }});
1276                                 object [] cb_args = new object [] {address, method, data, userToken};
1277                                 async_thread.Start (cb_args);
1278                         }
1279                 }
1280
1281                 //    UploadValuesAsync
1282
1283                 public void UploadValuesAsync (Uri address, NameValueCollection values)
1284                 {
1285                         UploadValuesAsync (address, null, values);
1286                 }
1287
1288                 public void UploadValuesAsync (Uri address, string method, NameValueCollection values)
1289                 {
1290                         UploadValuesAsync (address, method, values, null);
1291                 }
1292
1293                 public void UploadValuesAsync (Uri address, string method, NameValueCollection values, object userToken)
1294                 {
1295                         if (address == null)
1296                                 throw new ArgumentNullException ("address");
1297                         if (values == null)
1298                                 throw new ArgumentNullException ("values");
1299
1300                         lock (this) {
1301                                 CheckBusy ();
1302                                 async = true;
1303
1304                                 async_thread = new Thread (delegate (object state) {
1305                                         object [] args = (object []) state;
1306                                         try {
1307                                                 byte [] data = UploadValuesCore ((Uri) args [0], (string) args [1], (NameValueCollection) args [2], args [3]);
1308                                                 OnUploadValuesCompleted (
1309                                                         new UploadValuesCompletedEventArgs (data, null, false, args [3]));
1310                                         } catch (ThreadInterruptedException){
1311                                                 OnUploadValuesCompleted (
1312                                                         new UploadValuesCompletedEventArgs (null, null, true, args [3]));
1313                                         } catch (Exception e){
1314                                                 OnUploadValuesCompleted (
1315                                                         new UploadValuesCompletedEventArgs (null, e, false, args [3]));
1316                                         }});
1317                                 object [] cb_args = new object [] {address, method, values,  userToken};
1318                                 async_thread.Start (cb_args);
1319                         }
1320                 }
1321
1322                 protected virtual void OnDownloadDataCompleted (DownloadDataCompletedEventArgs args)
1323                 {
1324                         CompleteAsync ();
1325                         if (DownloadDataCompleted != null)
1326                                 DownloadDataCompleted (this, args);
1327                 }
1328
1329                 protected virtual void OnDownloadFileCompleted (AsyncCompletedEventArgs args)
1330                 {
1331                         CompleteAsync ();
1332                         if (DownloadFileCompleted != null)
1333                                 DownloadFileCompleted (this, args);
1334                 }
1335
1336                 protected virtual void OnDownloadProgressChanged (DownloadProgressChangedEventArgs e)
1337                 {
1338                         if (DownloadProgressChanged != null)
1339                                 DownloadProgressChanged (this, e);
1340                 }
1341
1342                 protected virtual void OnDownloadStringCompleted (DownloadStringCompletedEventArgs args)
1343                 {
1344                         CompleteAsync ();
1345                         if (DownloadStringCompleted != null)
1346                                 DownloadStringCompleted (this, args);
1347                 }
1348
1349                 protected virtual void OnOpenReadCompleted (OpenReadCompletedEventArgs args)
1350                 {
1351                         CompleteAsync ();
1352                         if (OpenReadCompleted != null)
1353                                 OpenReadCompleted (this, args);
1354                 }
1355
1356                 protected virtual void OnOpenWriteCompleted (OpenWriteCompletedEventArgs args)
1357                 {
1358                         CompleteAsync ();
1359                         if (OpenWriteCompleted != null)
1360                                 OpenWriteCompleted (this, args);
1361                 }
1362
1363                 protected virtual void OnUploadDataCompleted (UploadDataCompletedEventArgs args)
1364                 {
1365                         CompleteAsync ();
1366                         if (UploadDataCompleted != null)
1367                                 UploadDataCompleted (this, args);
1368                 }
1369
1370                 protected virtual void OnUploadFileCompleted (UploadFileCompletedEventArgs args)
1371                 {
1372                         CompleteAsync ();
1373                         if (UploadFileCompleted != null)
1374                                 UploadFileCompleted (this, args);
1375                 }
1376
1377                 protected virtual void OnUploadProgressChanged (UploadProgressChangedEventArgs e)
1378                 {
1379                         if (UploadProgressChanged != null)
1380                                 UploadProgressChanged (this, e);
1381                 }
1382
1383                 protected virtual void OnUploadStringCompleted (UploadStringCompletedEventArgs args)
1384                 {
1385                         CompleteAsync ();
1386                         if (UploadStringCompleted != null)
1387                                 UploadStringCompleted (this, args);
1388                 }
1389
1390                 protected virtual void OnUploadValuesCompleted (UploadValuesCompletedEventArgs args)
1391                 {
1392                         CompleteAsync ();
1393                         if (UploadValuesCompleted != null)
1394                                 UploadValuesCompleted (this, args);
1395                 }
1396
1397                 protected virtual WebResponse GetWebResponse (WebRequest request, IAsyncResult result)
1398                 {
1399                         WebResponse response = request.EndGetResponse (result);
1400                         responseHeaders = response.Headers;
1401                         return response;
1402                 }
1403
1404                 protected virtual WebRequest GetWebRequest (Uri address)
1405                 {
1406                         return WebRequest.Create (address);
1407                 }
1408
1409                 protected virtual WebResponse GetWebResponse (WebRequest request)
1410                 {
1411                         WebResponse response = request.GetResponse ();
1412                         responseHeaders = response.Headers;
1413                         return response;
1414                 }
1415
1416         }
1417 }
1418