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 [] realBoundary = Encoding.ASCII.GetBytes ("--" + boundary + "\r\n");
 537                                 reqStream.Write (realBoundary, 0, realBoundary.Length);
 538                                 string partHeaders = String.Format ("Content-Disposition: form-data; " +
 539                                                                     "name=\"file\"; filename=\"{0}\"\r\n" +
 540                                                                     "Content-Type: {1}\r\n\r\n",
 541                                                                     Path.GetFileName (fileName), fileCType);
 542
 543                                 byte [] partHeadersBytes = Encoding.UTF8.GetBytes (partHeaders);
 544                                 reqStream.Write (partHeadersBytes, 0, partHeadersBytes.Length);
 545                                 int nread;
 546                                 byte [] buffer = new byte [4096];
 547                                 while ((nread = fStream.Read (buffer, 0, 4096)) != 0)
 548                                         reqStream.Write (buffer, 0, nread);
 549
 550                                 reqStream.WriteByte ((byte) '\r');
 551                                 reqStream.WriteByte ((byte) '\n');
 552                                 reqStream.Write (realBoundary, 0, realBoundary.Length);
 553                                 reqStream.Close ();
 554                                 reqStream = null;
 555                                 resultBytes = ReadAll (request, userToken);
 556                         } catch (ThreadInterruptedException){
 557                                 if (request != null)
 558                                         request.Abort ();
 559                                 throw;
 560                         } finally {
 561                                 if (fStream != null)
 562                                         fStream.Close ();
 563
 564                                 if (reqStream != null)
 565                                         reqStream.Close ();
 566                         }
 567
 568                         return resultBytes;
 569                 }
 570
 571                 public byte[] UploadValues (string address, NameValueCollection data)
 572                 {
 573                         if (address == null)
 574                                 throw new ArgumentNullException ("address");
 575
 576                         return UploadValues (CreateUri (address), data);
 577                 }
 578
 579                 public byte[] UploadValues (string address, string method, NameValueCollection data)
 580                 {
 581                         if (address == null)
 582                                 throw new ArgumentNullException ("address");
 583                         return UploadValues (CreateUri (address), method, data);
 584                 }
 585
 586                 public byte[] UploadValues (Uri address, NameValueCollection data)
 587                 {
 588                         return UploadValues (address, (string) null, data);
 589                 }
 590
 591                 public byte[] UploadValues (Uri address, string method, NameValueCollection data)
 592                 {
 593                         if (address == null)
 594                                 throw new ArgumentNullException ("address");
 595                         if (data == null)
 596                                 throw new ArgumentNullException ("data");
 597
 598                         try {
 599                                 SetBusy ();
 600                                 async = false;
 601                                 return UploadValuesCore (address, method, data, null);
 602                         } catch (WebException) {
 603                                 throw;
 604                         } catch (Exception ex) {
 605                                 throw new WebException ("An error occurred " +
 606                                         "performing a WebClient request.", ex);
 607                         } finally {
 608                                 is_busy = false;
 609                         }
 610                 }
 611
 612                 byte[] UploadValuesCore (Uri uri, string method, NameValueCollection data, object userToken)
 613                 {
 614                         string cType = Headers ["Content-Type"];
 615                         if (cType != null && String.Compare (cType, urlEncodedCType, true) != 0)
 616                                 throw new WebException ("Content-Type header cannot be changed from its default " +
 617                                                         "value for this request.");
 618
 619                         Headers ["Content-Type"] = urlEncodedCType;
 620                         WebRequest request = SetupRequest (uri, method, true);
 621                         try {
 622                                 MemoryStream tmpStream = new MemoryStream ();
 623                                 foreach (string key in data) {
 624                                         byte [] bytes = Encoding.UTF8.GetBytes (key);
 625                                         UrlEncodeAndWrite (tmpStream, bytes);
 626                                         tmpStream.WriteByte ((byte) '=');
 627                                         bytes = Encoding.UTF8.GetBytes (data [key]);
 628                                         UrlEncodeAndWrite (tmpStream, bytes);
 629                                         tmpStream.WriteByte ((byte) '&');
 630                                 }
 631
 632                                 int length = (int) tmpStream.Length;
 633                                 if (length > 0)
 634                                         tmpStream.SetLength (--length); // remove trailing '&'
 635
 636                                 byte [] buf = tmpStream.GetBuffer ();
 637                                 request.ContentLength = length;
 638                                 using (Stream rqStream = request.GetRequestStream ()) {
 639                                         rqStream.Write (buf, 0, length);
 640                                 }
 641                                 tmpStream.Close ();
 642
 643                                 return ReadAll (request, userToken);
 644                         } catch (ThreadInterruptedException) {
 645                                 request.Abort ();
 646                                 throw;
 647                         }
 648                 }
 649
 650                 public string DownloadString (string address)
 651                 {
 652                         if (address == null)
 653                                 throw new ArgumentNullException ("address");
 654
 655                         return encoding.GetString (DownloadData (CreateUri (address)));
 656                 }
 657
 658                 public string DownloadString (Uri address)
 659                 {
 660                         if (address == null)
 661                                 throw new ArgumentNullException ("address");
 662
 663                         return encoding.GetString (DownloadData (CreateUri (address)));
 664                 }
 665
 666                 public string UploadString (string address, string data)
 667                 {
 668                         if (address == null)
 669                                 throw new ArgumentNullException ("address");
 670                         if (data == null)
 671                                 throw new ArgumentNullException ("data");
 672
 673                         byte [] resp = UploadData (address, encoding.GetBytes (data));
 674                         return encoding.GetString (resp);
 675                 }
 676
 677                 public string UploadString (string address, string method, string data)
 678                 {
 679                         if (address == null)
 680                                 throw new ArgumentNullException ("address");
 681                         if (data == null)
 682                                 throw new ArgumentNullException ("data");
 683
 684                         byte [] resp = UploadData (address, method, encoding.GetBytes (data));
 685                         return encoding.GetString (resp);
 686                 }
 687
 688                 public string UploadString (Uri address, string data)
 689                 {
 690                         if (address == null)
 691                                 throw new ArgumentNullException ("address");
 692                         if (data == null)
 693                                 throw new ArgumentNullException ("data");
 694
 695                         byte [] resp = UploadData (address, encoding.GetBytes (data));
 696                         return encoding.GetString (resp);
 697                 }
 698
 699                 public string UploadString (Uri address, string method, string data)
 700                 {
 701                         if (address == null)
 702                                 throw new ArgumentNullException ("address");
 703                         if (data == null)
 704                                 throw new ArgumentNullException ("data");
 705
 706                         byte [] resp = UploadData (address, method, encoding.GetBytes (data));
 707                         return encoding.GetString (resp);
 708                 }
 709
 710                 public event DownloadDataCompletedEventHandler DownloadDataCompleted;
 711                 public event AsyncCompletedEventHandler DownloadFileCompleted;
 712                 public event DownloadProgressChangedEventHandler DownloadProgressChanged;
 713                 public event DownloadStringCompletedEventHandler DownloadStringCompleted;
 714                 public event OpenReadCompletedEventHandler OpenReadCompleted;
 715                 public event OpenWriteCompletedEventHandler OpenWriteCompleted;
 716                 public event UploadDataCompletedEventHandler UploadDataCompleted;
 717                 public event UploadFileCompletedEventHandler UploadFileCompleted;
 718                 public event UploadProgressChangedEventHandler UploadProgressChanged;
 719                 public event UploadStringCompletedEventHandler UploadStringCompleted;
 720                 public event UploadValuesCompletedEventHandler UploadValuesCompleted;
 721
 722                 Uri CreateUri (string address)
 723                 {
 724                         Uri uri;
 725                         try {
 726                                 if (baseAddress == null)
 727                                         uri = new Uri (address);
 728                                 else
 729                                         uri = new Uri (baseAddress, address);
 730                                 return CreateUri (uri);
 731                         } catch {
 732                         }
 733                         return new Uri (Path.GetFullPath (address));
 734                 }
 735
 736                 Uri CreateUri (Uri address)
 737                 {
 738                         Uri result = address;
 739                         if (baseAddress != null && !result.IsAbsoluteUri) {
 740                                 try {
 741                                         result = new Uri (baseAddress, result.OriginalString);
 742                                 } catch {
 743                                         return result; // Not much we can do here.
 744                                 }
 745                         }
 746
 747                         string query = result.Query;
 748                         if (String.IsNullOrEmpty (query))
 749                                 query = GetQueryString (true);
 750                         UriBuilder builder = new UriBuilder (address);
 751                         if (!String.IsNullOrEmpty (query))
 752                                 builder.Query = query.Substring (1);
 753                         return builder.Uri;
 754                 }
 755
 756                 string GetQueryString (bool add_qmark)
 757                 {
 758                         if (queryString == null || queryString.Count == 0)
 759                                 return null;
 760
 761                         StringBuilder sb = new StringBuilder ();
 762                         if (add_qmark)
 763                                 sb.Append ('?');
 764
 765                         foreach (string key in queryString)
 766                                 sb.AppendFormat ("{0}={1}&", key, UrlEncode (queryString [key]));
 767
 768                         if (sb.Length != 0)
 769                                 sb.Length--; // removes last '&' or the '?' if empty.
 770
 771                         if (sb.Length == 0)
 772                                 return null;
 773
 774                         return sb.ToString ();
 775                 }
 776
 777                 WebRequest SetupRequest (Uri uri)
 778                 {
 779                         WebRequest request = GetWebRequest (uri);
 780                         if (Proxy != null)
 781                                 request.Proxy = Proxy;
 782                         request.Credentials = credentials;
 783
 784                         // Special headers. These are properties of HttpWebRequest.
 785                         // What do we do with other requests differnt from HttpWebRequest?
 786                         if (headers != null && headers.Count != 0 && (request is HttpWebRequest)) {
 787                                 HttpWebRequest req = (HttpWebRequest) request;
 788                                 string expect = headers ["Expect"];
 789                                 string contentType = headers ["Content-Type"];
 790                                 string accept = headers ["Accept"];
 791                                 string connection = headers ["Connection"];
 792                                 string userAgent = headers ["User-Agent"];
 793                                 string referer = headers ["Referer"];
 794                                 headers.RemoveInternal ("Expect");
 795                                 headers.RemoveInternal ("Content-Type");
 796                                 headers.RemoveInternal ("Accept");
 797                                 headers.RemoveInternal ("Connection");
 798                                 headers.RemoveInternal ("Referer");
 799                                 headers.RemoveInternal ("User-Agent");
 800                                 request.Headers = headers;
 801
 802                                 if (expect != null && expect.Length > 0)
 803                                         req.Expect = expect;
 804
 805                                 if (accept != null && accept.Length > 0)
 806                                         req.Accept = accept;
 807
 808                                 if (contentType != null && contentType.Length > 0)
 809                                         req.ContentType = contentType;
 810
 811                                 if (connection != null && connection.Length > 0)
 812                                         req.Connection = connection;
 813
 814                                 if (userAgent != null && userAgent.Length > 0)
 815                                         req.UserAgent = userAgent;
 816
 817                                 if (referer != null && referer.Length > 0)
 818                                         req.Referer = referer;
 819                         }
 820
 821                         responseHeaders = null;
 822                         return request;
 823                 }
 824
 825                 WebRequest SetupRequest (Uri uri, string method, bool is_upload)
 826                 {
 827                         WebRequest request = SetupRequest (uri);
 828                         request.Method = DetermineMethod (uri, method, is_upload);
 829                         return request;
 830                 }
 831
 832                 byte [] ReadAll (WebRequest request, object userToken)
 833                 {
 834                         WebResponse response = GetWebResponse (request);
 835                         Stream stream = response.GetResponseStream ();
 836                         int length = (int) response.ContentLength;
 837                         HttpWebRequest wreq = request as HttpWebRequest;
 838
 839                         if (length > -1 && wreq != null && (int) wreq.AutomaticDecompression != 0) {
 840                                 string content_encoding = ((HttpWebResponse) response).ContentEncoding;
 841                                 if (((content_encoding == "gzip" && (wreq.AutomaticDecompression & DecompressionMethods.GZip) != 0)) ||
 842                                         ((content_encoding == "deflate" && (wreq.AutomaticDecompression & DecompressionMethods.Deflate) != 0)))
 843                                         length = -1;
 844                         }
 845
 846                         MemoryStream ms = null;
 847                         bool nolength = (length == -1);
 848                         int size = ((nolength) ? 8192 : length);
 849                         if (nolength)
 850                                 ms = new MemoryStream ();
 851
 852 //                      long total = 0;
 853                         int nread = 0;
 854                         int offset = 0;
 855                         byte [] buffer = new byte [size];
 856                         while ((nread = stream.Read (buffer, offset, size)) != 0) {
 857                                 if (nolength) {
 858                                         ms.Write (buffer, 0, nread);
 859                                 } else {
 860                                         offset += nread;
 861                                         size -= nread;
 862                                 }
 863                                 if (async){
 864 //                                      total += nread;
 865                                         OnDownloadProgressChanged (new DownloadProgressChangedEventArgs (nread, length, userToken));
 866                                 }
 867                         }
 868
 869                         if (nolength)
 870                                 return ms.ToArray ();
 871
 872                         return buffer;
 873                 }
 874
 875                 string UrlEncode (string str)
 876                 {
 877                         StringBuilder result = new StringBuilder ();
 878
 879                         int len = str.Length;
 880                         for (int i = 0; i < len; i++) {
 881                                 char c = str [i];
 882                                 if (c == ' ')
 883                                         result.Append ('+');
 884                                 else if ((c < '0' && c != '-' && c != '.') ||
 885                                          (c < 'A' && c > '9') ||
 886                                          (c > 'Z' && c < 'a' && c != '_') ||
 887                                          (c > 'z')) {
 888                                         result.Append ('%');
 889                                         int idx = ((int) c) >> 4;
 890                                         result.Append ((char) hexBytes [idx]);
 891                                         idx = ((int) c) & 0x0F;
 892                                         result.Append ((char) hexBytes [idx]);
 893                                 } else {
 894                                         result.Append (c);
 895                                 }
 896                         }
 897
 898                         return result.ToString ();
 899                 }
 900
 901                 static void UrlEncodeAndWrite (Stream stream, byte [] bytes)
 902                 {
 903                         if (bytes == null)
 904                                 return;
 905
 906                         int len = bytes.Length;
 907                         if (len == 0)
 908                                 return;
 909
 910                         for (int i = 0; i < len; i++) {
 911                                 char c = (char) bytes [i];
 912                                 if (c == ' ')
 913                                         stream.WriteByte ((byte) '+');
 914                                 else if ((c < '0' && c != '-' && c != '.') ||
 915                                          (c < 'A' && c > '9') ||
 916                                          (c > 'Z' && c < 'a' && c != '_') ||
 917                                          (c > 'z')) {
 918                                         stream.WriteByte ((byte) '%');
 919                                         int idx = ((int) c) >> 4;
 920                                         stream.WriteByte (hexBytes [idx]);
 921                                         idx = ((int) c) & 0x0F;
 922                                         stream.WriteByte (hexBytes [idx]);
 923                                 } else {
 924                                         stream.WriteByte ((byte) c);
 925                                 }
 926                         }
 927                 }
 928
 929                 public void CancelAsync ()
 930                 {
 931                         lock (this){
 932                                 if (async_thread == null)
 933                                         return;
 934
 935                                 //
 936                                 // We first flag things as done, in case the Interrupt hangs
 937                                 // or the thread decides to hang in some other way inside the
 938                                 // event handlers, or if we are stuck somewhere else.  This
 939                                 // ensures that the WebClient object is reusable immediately
 940                                 //
 941                                 Thread t = async_thread;
 942                                 CompleteAsync ();
 943                                 t.Interrupt ();
 944                         }
 945                 }
 946
 947                 void CompleteAsync ()
 948                 {
 949                         lock (this){
 950                                 is_busy = false;
 951                                 async_thread = null;
 952                         }
 953                 }
 954
 955                 //    DownloadDataAsync
 956
 957                 public void DownloadDataAsync (Uri address)
 958                 {
 959                         DownloadDataAsync (address, null);
 960                 }
 961
 962                 public void DownloadDataAsync (Uri address, object userToken)
 963                 {
 964                         if (address == null)
 965                                 throw new ArgumentNullException ("address");
 966
 967                         lock (this) {
 968                                 SetBusy ();
 969                                 async = true;
 970
 971                                 async_thread = new Thread (delegate (object state) {
 972                                         object [] args = (object []) state;
 973                                         try {
 974                                                 byte [] data = DownloadDataCore ((Uri) args [0], args [1]);
 975                                                 OnDownloadDataCompleted (
 976                                                         new DownloadDataCompletedEventArgs (data, null, false, args [1]));
 977                                         } catch (ThreadInterruptedException){
 978                                                 OnDownloadDataCompleted (
 979                                                         new DownloadDataCompletedEventArgs (null, null, true, args [1]));
 980                                                 throw;
 981                                         } catch (Exception e){
 982                                                 OnDownloadDataCompleted (
 983                                                         new DownloadDataCompletedEventArgs (null, e, false, args [1]));
 984                                         }
 985                                 });
 986                                 object [] cb_args = new object [] {address, userToken};
 987                                 async_thread.Start (cb_args);
 988                         }
 989                 }
 990
 991                 //    DownloadFileAsync
 992
 993                 public void DownloadFileAsync (Uri address, string fileName)
 994                 {
 995                         DownloadFileAsync (address, fileName, null);
 996                 }
 997
 998                 public void DownloadFileAsync (Uri address, string fileName, object userToken)
 999                 {
1000                         if (address == null)
1001                                 throw new ArgumentNullException ("address");
1002                         if (fileName == null)
1003                                 throw new ArgumentNullException ("fileName");
1004
1005                         lock (this) {
1006                                 SetBusy ();
1007                                 async = true;
1008
1009                                 async_thread = new Thread (delegate (object state) {
1010                                         object [] args = (object []) state;
1011                                         try {
1012                                                 DownloadFileCore ((Uri) args [0], (string) args [1], args [2]);
1013                                                 OnDownloadFileCompleted (
1014                                                         new AsyncCompletedEventArgs (null, false, args [2]));
1015                                         } catch (ThreadInterruptedException){
1016                                                 OnDownloadFileCompleted (
1017                                                         new AsyncCompletedEventArgs (null, true, args [2]));
1018                                         } catch (Exception e){
1019                                                 OnDownloadFileCompleted (
1020                                                         new AsyncCompletedEventArgs (e, false, args [2]));
1021                                         }});
1022                                 object [] cb_args = new object [] {address, fileName, userToken};
1023                                 async_thread.Start (cb_args);
1024                         }
1025                 }
1026
1027                 //    DownloadStringAsync
1028
1029                 public void DownloadStringAsync (Uri address)
1030                 {
1031                         DownloadStringAsync (address, null);
1032                 }
1033
1034                 public void DownloadStringAsync (Uri address, object userToken)
1035                 {
1036                         if (address == null)
1037                                 throw new ArgumentNullException ("address");
1038
1039                         lock (this) {
1040                                 SetBusy ();
1041                                 async = true;
1042
1043                                 async_thread = new Thread (delegate (object state) {
1044                                         object [] args = (object []) state;
1045                                         try {
1046                                                 string data = encoding.GetString (DownloadDataCore ((Uri) args [0], args [1]));
1047                                                 OnDownloadStringCompleted (
1048                                                         new DownloadStringCompletedEventArgs (data, null, false, args [1]));
1049                                         } catch (ThreadInterruptedException){
1050                                                 OnDownloadStringCompleted (
1051                                                         new DownloadStringCompletedEventArgs (null, null, true, args [1]));
1052                                         } catch (Exception e){
1053                                                 OnDownloadStringCompleted (
1054                                                         new DownloadStringCompletedEventArgs (null, e, false, args [1]));
1055                                         }});
1056                                 object [] cb_args = new object [] {address, userToken};
1057                                 async_thread.Start (cb_args);
1058                         }
1059                 }
1060
1061                 //    OpenReadAsync
1062
1063                 public void OpenReadAsync (Uri address)
1064                 {
1065                         OpenReadAsync (address, null);
1066                 }
1067
1068                 public void OpenReadAsync (Uri address, object userToken)
1069                 {
1070                         if (address == null)
1071                                 throw new ArgumentNullException ("address");
1072
1073                         lock (this) {
1074                                 SetBusy ();
1075                                 async = true;
1076
1077                                 async_thread = new Thread (delegate (object state) {
1078                                         object [] args = (object []) state;
1079                                         WebRequest request = null;
1080                                         try {
1081                                                 request = SetupRequest ((Uri) args [0]);
1082                                                 WebResponse response = GetWebResponse (request);
1083                                                 Stream stream = response.GetResponseStream ();
1084                                                 OnOpenReadCompleted (
1085                                                         new OpenReadCompletedEventArgs (stream, null, false, args [1]));
1086                                         } catch (ThreadInterruptedException){
1087                                                 if (request != null)
1088                                                         request.Abort ();
1089
1090                                                 OnOpenReadCompleted (new OpenReadCompletedEventArgs (null, null, true, args [1]));
1091                                         } catch (Exception e){
1092                                                 OnOpenReadCompleted (new OpenReadCompletedEventArgs (null, e, false, args [1]));
1093                                         } });
1094                                 object [] cb_args = new object [] {address, userToken};
1095                                 async_thread.Start (cb_args);
1096                         }
1097                 }
1098
1099                 //    OpenWriteAsync
1100
1101                 public void OpenWriteAsync (Uri address)
1102                 {
1103                         OpenWriteAsync (address, null);
1104                 }
1105
1106                 public void OpenWriteAsync (Uri address, string method)
1107                 {
1108                         OpenWriteAsync (address, method, null);
1109                 }
1110
1111                 public void OpenWriteAsync (Uri address, string method, object userToken)
1112                 {
1113                         if (address == null)
1114                                 throw new ArgumentNullException ("address");
1115
1116                         lock (this) {
1117                                 SetBusy ();
1118                                 async = true;
1119
1120                                 async_thread = new Thread (delegate (object state) {
1121                                         object [] args = (object []) state;
1122                                         WebRequest request = null;
1123                                         try {
1124                                                 request = SetupRequest ((Uri) args [0], (string) args [1], true);
1125                                                 Stream stream = request.GetRequestStream ();
1126                                                 OnOpenWriteCompleted (
1127                                                         new OpenWriteCompletedEventArgs (stream, null, false, args [2]));
1128                                         } catch (ThreadInterruptedException){
1129                                                 if (request != null)
1130                                                         request.Abort ();
1131                                                 OnOpenWriteCompleted (
1132                                                         new OpenWriteCompletedEventArgs (null, null, true, args [2]));
1133                                         } catch (Exception e){
1134                                                 OnOpenWriteCompleted (
1135                                                         new OpenWriteCompletedEventArgs (null, e, false, args [2]));
1136                                         }});
1137                                 object [] cb_args = new object [] {address, method, userToken};
1138                                 async_thread.Start (cb_args);
1139                         }
1140                 }
1141
1142                 //    UploadDataAsync
1143
1144                 public void UploadDataAsync (Uri address, byte [] data)
1145                 {
1146                         UploadDataAsync (address, null, data);
1147                 }
1148
1149                 public void UploadDataAsync (Uri address, string method, byte [] data)
1150                 {
1151                         UploadDataAsync (address, method, data, null);
1152                 }
1153
1154                 public void UploadDataAsync (Uri address, string method, byte [] data, object userToken)
1155                 {
1156                         if (address == null)
1157                                 throw new ArgumentNullException ("address");
1158                         if (data == null)
1159                                 throw new ArgumentNullException ("data");
1160
1161                         lock (this) {
1162                                 SetBusy ();
1163                                 async = true;
1164
1165                                 async_thread = new Thread (delegate (object state) {
1166                                         object [] args = (object []) state;
1167                                         byte [] data2;
1168
1169                                         try {
1170                                                 data2 = UploadDataCore ((Uri) args [0], (string) args [1], (byte []) args [2], args [3]);
1171
1172                                                 OnUploadDataCompleted (
1173                                                         new UploadDataCompletedEventArgs (data2, null, false, args [3]));
1174                                         } catch (ThreadInterruptedException){
1175                                                 OnUploadDataCompleted (
1176                                                         new UploadDataCompletedEventArgs (null, null, true, args [3]));
1177                                         } catch (Exception e){
1178                                                 OnUploadDataCompleted (
1179                                                         new UploadDataCompletedEventArgs (null, e, false, args [3]));
1180                                         }});
1181                                 object [] cb_args = new object [] {address, method, data,  userToken};
1182                                 async_thread.Start (cb_args);
1183                         }
1184                 }
1185
1186                 //    UploadFileAsync
1187
1188                 public void UploadFileAsync (Uri address, string fileName)
1189                 {
1190                         UploadFileAsync (address, null, fileName);
1191                 }
1192
1193                 public void UploadFileAsync (Uri address, string method, string fileName)
1194                 {
1195                         UploadFileAsync (address, method, fileName, null);
1196                 }
1197
1198                 public void UploadFileAsync (Uri address, string method, string fileName, object userToken)
1199                 {
1200                         if (address == null)
1201                                 throw new ArgumentNullException ("address");
1202                         if (fileName == null)
1203                                 throw new ArgumentNullException ("fileName");
1204
1205                         lock (this) {
1206                                 SetBusy ();
1207                                 async = true;
1208
1209                                 async_thread = new Thread (delegate (object state) {
1210                                         object [] args = (object []) state;
1211                                         byte [] data;
1212
1213                                         try {
1214                                                 data = UploadFileCore ((Uri) args [0], (string) args [1], (string) args [2], args [3]);
1215                                                 OnUploadFileCompleted (
1216                                                         new UploadFileCompletedEventArgs (data, null, false, args [3]));
1217                                         } catch (ThreadInterruptedException){
1218                                                 OnUploadFileCompleted (
1219                                                         new UploadFileCompletedEventArgs (null, null, true, args [3]));
1220                                         } catch (Exception e){
1221                                                 OnUploadFileCompleted (
1222                                                         new UploadFileCompletedEventArgs (null, e, false, args [3]));
1223                                         }});
1224                                 object [] cb_args = new object [] {address, method, fileName,  userToken};
1225                                 async_thread.Start (cb_args);
1226                         }
1227                 }
1228
1229                 //    UploadStringAsync
1230
1231                 public void UploadStringAsync (Uri address, string data)
1232                 {
1233                         UploadStringAsync (address, null, data);
1234                 }
1235
1236                 public void UploadStringAsync (Uri address, string method, string data)
1237                 {
1238                         UploadStringAsync (address, method, data, null);
1239                 }
1240
1241                 public void UploadStringAsync (Uri address, string method, string data, object userToken)
1242                 {
1243                         if (address == null)
1244                                 throw new ArgumentNullException ("address");
1245                         if (data == null)
1246                                 throw new ArgumentNullException ("data");
1247
1248                         lock (this) {
1249                                 CheckBusy ();
1250                                 async = true;
1251
1252                                 async_thread = new Thread (delegate (object state) {
1253                                         object [] args = (object []) state;
1254
1255                                         try {
1256                                                 string data2 = UploadString ((Uri) args [0], (string) args [1], (string) args [2]);
1257                                                 OnUploadStringCompleted (
1258                                                         new UploadStringCompletedEventArgs (data2, null, false, args [3]));
1259                                         } catch (ThreadInterruptedException){
1260                                                 OnUploadStringCompleted (
1261                                                         new UploadStringCompletedEventArgs (null, null, true, args [3]));
1262                                         } catch (Exception e){
1263                                                 OnUploadStringCompleted (
1264                                                         new UploadStringCompletedEventArgs (null, e, false, args [3]));
1265                                         }});
1266                                 object [] cb_args = new object [] {address, method, data, userToken};
1267                                 async_thread.Start (cb_args);
1268                         }
1269                 }
1270
1271                 //    UploadValuesAsync
1272
1273                 public void UploadValuesAsync (Uri address, NameValueCollection values)
1274                 {
1275                         UploadValuesAsync (address, null, values);
1276                 }
1277
1278                 public void UploadValuesAsync (Uri address, string method, NameValueCollection values)
1279                 {
1280                         UploadValuesAsync (address, method, values, null);
1281                 }
1282
1283                 public void UploadValuesAsync (Uri address, string method, NameValueCollection values, object userToken)
1284                 {
1285                         if (address == null)
1286                                 throw new ArgumentNullException ("address");
1287                         if (values == null)
1288                                 throw new ArgumentNullException ("values");
1289
1290                         lock (this) {
1291                                 CheckBusy ();
1292                                 async = true;
1293
1294                                 async_thread = new Thread (delegate (object state) {
1295                                         object [] args = (object []) state;
1296                                         try {
1297                                                 byte [] data = UploadValuesCore ((Uri) args [0], (string) args [1], (NameValueCollection) args [2], args [3]);
1298                                                 OnUploadValuesCompleted (
1299                                                         new UploadValuesCompletedEventArgs (data, null, false, args [3]));
1300                                         } catch (ThreadInterruptedException){
1301                                                 OnUploadValuesCompleted (
1302                                                         new UploadValuesCompletedEventArgs (null, null, true, args [3]));
1303                                         } catch (Exception e){
1304                                                 OnUploadValuesCompleted (
1305                                                         new UploadValuesCompletedEventArgs (null, e, false, args [3]));
1306                                         }});
1307                                 object [] cb_args = new object [] {address, method, values,  userToken};
1308                                 async_thread.Start (cb_args);
1309                         }
1310                 }
1311
1312                 protected virtual void OnDownloadDataCompleted (DownloadDataCompletedEventArgs args)
1313                 {
1314                         CompleteAsync ();
1315                         if (DownloadDataCompleted != null)
1316                                 DownloadDataCompleted (this, args);
1317                 }
1318
1319                 protected virtual void OnDownloadFileCompleted (AsyncCompletedEventArgs args)
1320                 {
1321                         CompleteAsync ();
1322                         if (DownloadFileCompleted != null)
1323                                 DownloadFileCompleted (this, args);
1324                 }
1325
1326                 protected virtual void OnDownloadProgressChanged (DownloadProgressChangedEventArgs e)
1327                 {
1328                         if (DownloadProgressChanged != null)
1329                                 DownloadProgressChanged (this, e);
1330                 }
1331
1332                 protected virtual void OnDownloadStringCompleted (DownloadStringCompletedEventArgs args)
1333                 {
1334                         CompleteAsync ();
1335                         if (DownloadStringCompleted != null)
1336                                 DownloadStringCompleted (this, args);
1337                 }
1338
1339                 protected virtual void OnOpenReadCompleted (OpenReadCompletedEventArgs args)
1340                 {
1341                         CompleteAsync ();
1342                         if (OpenReadCompleted != null)
1343                                 OpenReadCompleted (this, args);
1344                 }
1345
1346                 protected virtual void OnOpenWriteCompleted (OpenWriteCompletedEventArgs args)
1347                 {
1348                         CompleteAsync ();
1349                         if (OpenWriteCompleted != null)
1350                                 OpenWriteCompleted (this, args);
1351                 }
1352
1353                 protected virtual void OnUploadDataCompleted (UploadDataCompletedEventArgs args)
1354                 {
1355                         CompleteAsync ();
1356                         if (UploadDataCompleted != null)
1357                                 UploadDataCompleted (this, args);
1358                 }
1359
1360                 protected virtual void OnUploadFileCompleted (UploadFileCompletedEventArgs args)
1361                 {
1362                         CompleteAsync ();
1363                         if (UploadFileCompleted != null)
1364                                 UploadFileCompleted (this, args);
1365                 }
1366
1367                 protected virtual void OnUploadProgressChanged (UploadProgressChangedEventArgs e)
1368                 {
1369                         if (UploadProgressChanged != null)
1370                                 UploadProgressChanged (this, e);
1371                 }
1372
1373                 protected virtual void OnUploadStringCompleted (UploadStringCompletedEventArgs args)
1374                 {
1375                         CompleteAsync ();
1376                         if (UploadStringCompleted != null)
1377                                 UploadStringCompleted (this, args);
1378                 }
1379
1380                 protected virtual void OnUploadValuesCompleted (UploadValuesCompletedEventArgs args)
1381                 {
1382                         CompleteAsync ();
1383                         if (UploadValuesCompleted != null)
1384                                 UploadValuesCompleted (this, args);
1385                 }
1386
1387                 protected virtual WebResponse GetWebResponse (WebRequest request, IAsyncResult result)
1388                 {
1389                         WebResponse response = request.EndGetResponse (result);
1390                         responseHeaders = response.Headers;
1391                         return response;
1392                 }
1393
1394                 protected virtual WebRequest GetWebRequest (Uri address)
1395                 {
1396                         return WebRequest.Create (address);
1397                 }
1398
1399                 protected virtual WebResponse GetWebResponse (WebRequest request)
1400                 {
1401                         WebResponse response = request.GetResponse ();
1402                         responseHeaders = response.Headers;
1403                         return response;
1404                 }
1405
1406         }
1407 }
1408