mcs/class/corlib/Microsoft.Win32/RegistryKey.cs

   1 //
   2 // RegistryKey.cs: a single node in the Windows registry
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Erik LeBel (eriklebel@yahoo.ca)
   7 //   Gert Driesen (drieseng@users.sourceforge.net)
   8 //
   9 //
  10 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System;
  33 using System.IO;
  34 using System.Collections;
  35 using System.Diagnostics;
  36 using System.Runtime.InteropServices;
  37 using System.Security;
  38 using System.Text;
  39 using System.Security.AccessControl;
  40 using System.Security.Permissions;
  41 using Microsoft.Win32.SafeHandles;
  42
  43 namespace Microsoft.Win32
  44 {
  45
  46 #if MOBILE && !WIN_PLATFORM
  47         public sealed class RegistryKey : IDisposable
  48         {
  49                 internal RegistryKey (RegistryHive hiveId)
  50                 {
  51                         throw new PlatformNotSupportedException ();
  52                 }
  53
  54                 public void Dispose ()
  55                 {
  56                 }
  57
  58                 public RegistryKey CreateSubKey (string subkey)
  59                 {
  60                         throw new PlatformNotSupportedException ();
  61                 }
  62
  63                 public RegistryKey CreateSubKey (String subkey, bool writable)
  64                 {
  65                         throw new PlatformNotSupportedException ();
  66                 }
  67
  68                 public RegistryKey CreateSubKey (String subkey, bool writable, RegistryOptions options)
  69                 {
  70                         throw new PlatformNotSupportedException ();
  71                 }
  72
  73                 public void DeleteSubKey (string subkey)
  74                 {
  75                 }
  76
  77                 public void DeleteSubKey (string subkey, bool throwOnMissingSubKey)
  78                 {
  79                 }
  80
  81                 public void DeleteSubKeyTree (string subkey)
  82                 {
  83                 }
  84
  85                 public void DeleteSubKeyTree (string subkey, bool throwOnMissingSubKey)
  86                 {
  87                 }
  88
  89                 public void DeleteValue (string name)
  90                 {
  91                 }
  92
  93                 public void DeleteValue (string name, bool throwOnMissingValue)
  94                 {
  95                 }
  96
  97                 public void Flush()
  98                 {
  99                 }
 100
 101                 public static RegistryKey FromHandle (SafeRegistryHandle handle)
 102                 {
 103                         throw new PlatformNotSupportedException ();
 104                 }
 105
 106                 public static RegistryKey FromHandle (SafeRegistryHandle handle, RegistryView view)
 107                 {
 108                         throw new PlatformNotSupportedException ();
 109                 }
 110
 111                 public string[] GetSubKeyNames ()
 112                 {
 113                         throw new PlatformNotSupportedException ();
 114                 }
 115
 116                 public object GetValue (string name)
 117                 {
 118                         throw new PlatformNotSupportedException ();
 119                 }
 120
 121                 public object GetValue (string name, object defaultValue)
 122                 {
 123                         throw new PlatformNotSupportedException ();
 124                 }
 125
 126                 public object GetValue (string name, object defaultValue, RegistryValueOptions options)
 127                 {
 128                         throw new PlatformNotSupportedException ();
 129                 }
 130
 131                 public RegistryValueKind GetValueKind (string name)
 132                 {
 133                         throw new PlatformNotSupportedException ();
 134                 }
 135
 136                 public string[] GetValueNames ()
 137                 {
 138                         throw new PlatformNotSupportedException ();
 139                 }
 140
 141                 public static RegistryKey OpenBaseKey (RegistryHive hKey, RegistryView view)
 142                 {
 143                         throw new PlatformNotSupportedException ();
 144                 }
 145
 146                 public RegistryKey OpenSubKey (string name)
 147                 {
 148                         throw new PlatformNotSupportedException ();
 149                 }
 150
 151                 public RegistryKey OpenSubKey (string name, bool writable)
 152                 {
 153                         throw new PlatformNotSupportedException ();
 154                 }
 155
 156                 public RegistryKey OpenSubKey (string name, RegistryRights rights)
 157                 {
 158                         throw new PlatformNotSupportedException ();
 159                 }
 160
 161                 public void SetValue (string name, object value)
 162                 {
 163                 }
 164
 165                 public void SetValue (string name, object value, RegistryValueKind valueKind)
 166                 {
 167                 }
 168
 169                 public SafeRegistryHandle Handle {
 170                         get { throw new PlatformNotSupportedException (); }
 171                 }
 172
 173                 public string Name {
 174                         get { throw new PlatformNotSupportedException (); }
 175                 }
 176
 177                 public int SubKeyCount {
 178                         get { throw new PlatformNotSupportedException (); }
 179                 }
 180
 181                 public int ValueCount {
 182                         get { throw new PlatformNotSupportedException (); }
 183                 }
 184
 185                 public RegistryView View {
 186                         get { throw new PlatformNotSupportedException (); }
 187                 }
 188         }
 189 #else
 190         /// <summary>
 191         ///     Wrapper class for Windows Registry Entry.
 192         /// </summary>
 193         [ComVisible (true)]
 194         public sealed class RegistryKey : MarshalByRefObject, IDisposable
 195         {
 196                 //
 197                 // This represents the backend data, used when creating the
 198                 // RegistryKey object
 199                 //
 200                 object handle;
 201                 SafeRegistryHandle safe_handle;
 202
 203                 object hive; // the RegistryHive if the key represents a base key
 204                 readonly string qname;  // the fully qualified registry key name
 205                 readonly bool isRemoteRoot;     // is an instance of a remote root key?
 206                 readonly bool isWritable;       // is the key openen in writable mode
 207
 208                 static readonly IRegistryApi RegistryApi;
 209
 210                 static RegistryKey ()
 211                 {
 212                         if (Path.DirectorySeparatorChar == '\\')
 213                                 RegistryApi = new Win32RegistryApi ();
 214                         else
 215                                 RegistryApi = new UnixRegistryApi ();
 216                 }
 217
 218                 /// <summary>
 219                 ///     Construct an instance of a root registry key entry.
 220                 /// </summary>
 221                 internal RegistryKey (RegistryHive hiveId) : this (hiveId,
 222                         new IntPtr ((int) hiveId), false)
 223                 {
 224                 }
 225
 226                 /// <summary>
 227                 ///     Construct an instance of a root registry key entry.
 228                 /// </summary>
 229                 internal RegistryKey (RegistryHive hiveId, IntPtr keyHandle, bool remoteRoot)
 230                 {
 231                         hive = hiveId;
 232                         handle = keyHandle;
 233                         qname = GetHiveName (hiveId);
 234                         isRemoteRoot = remoteRoot;
 235                         isWritable = true; // always consider root writable
 236                 }
 237
 238                 /// <summary>
 239                 ///     Construct an instance of a registry key entry.
 240                 /// </summary>
 241                 internal RegistryKey (object data, string keyName, bool writable)
 242                 {
 243                         handle = data;
 244                         qname = keyName;
 245                         isWritable = writable;
 246                 }
 247
 248                 static internal bool IsEquals (RegistryKey a, RegistryKey b)
 249                 {
 250                         return a.hive == b.hive && a.handle == b.handle && a.qname == b.qname  && a.isRemoteRoot == b.isRemoteRoot && a.isWritable == b.isWritable;
 251                 }
 252
 253                 #region PublicAPI
 254
 255                 /// <summary>
 256                 ///     Dispose of registry key object. Close the
 257                 ///     key if it's still open.
 258                 /// </summary>
 259                 public void Dispose ()
 260                 {
 261                         GC.SuppressFinalize (this);
 262                         Close ();
 263                 }
 264
 265                 /// <summary>
 266                 ///     Get the fully qualified registry key name.
 267                 /// </summary>
 268                 public string Name {
 269                         get { return qname; }
 270                 }
 271
 272
 273                 /// <summary>
 274                 ///     Flush the current registry state to disk.
 275                 /// </summary>
 276                 public void Flush()
 277                 {
 278                         RegistryApi.Flush (this);
 279                 }
 280
 281
 282                 /// <summary>
 283                 ///     Close the current registry key and flushes the state of the registry
 284                 /// right away.
 285                 /// </summary>
 286                 public void Close()
 287                 {
 288                         Flush ();
 289
 290                         // a handle to a remote hive must be closed, while one to a local
 291                         // hive should not be closed
 292                         if (!isRemoteRoot && IsRoot)
 293                                 return;
 294
 295                         RegistryApi.Close (this);
 296                         handle = null;
 297                         safe_handle = null;
 298                 }
 299
 300
 301                 /// <summary>
 302                 ///     get the number of sub-keys for this key
 303                 /// </summary>
 304                 public int SubKeyCount {
 305                         get {
 306                                 AssertKeyStillValid ();
 307
 308                                 return RegistryApi.SubKeyCount (this);
 309                         }
 310                 }
 311
 312
 313                 /// <summary>
 314                 ///     get the number of values for this key
 315                 /// </summary>
 316                 public int ValueCount {
 317                         get {
 318                                 AssertKeyStillValid ();
 319
 320                                 return RegistryApi.ValueCount (this);
 321                         }
 322                 }
 323
 324                 [ComVisible (false)]
 325                 [MonoTODO ("Not implemented in Unix")]
 326                 public SafeRegistryHandle Handle {
 327                         get {
 328                                 AssertKeyStillValid ();
 329
 330                                 if (safe_handle == null) {
 331                                         IntPtr h = RegistryApi.GetHandle (this);
 332                                         safe_handle = new SafeRegistryHandle (h, true);
 333                                 }
 334
 335                                 return safe_handle;
 336                         }
 337                 }
 338
 339                 [ComVisible (false)]
 340                 [MonoLimitation ("View is ignored in Mono.")]
 341                 public RegistryView View {
 342                         get {
 343                                 return RegistryView.Default;
 344                         }
 345                 }
 346
 347
 348                 /// <summary>
 349                 ///     Set a registry value.
 350                 /// </summary>
 351                 public void SetValue (string name, object value)
 352                 {
 353                         AssertKeyStillValid ();
 354
 355                         if (value == null)
 356                                 throw new ArgumentNullException ("value");
 357
 358                         if (name != null)
 359                                 AssertKeyNameLength (name);
 360
 361                         if (!IsWritable)
 362                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 363
 364                         RegistryApi.SetValue (this, name, value);
 365                 }
 366
 367                 [ComVisible (false)]
 368                 public void SetValue (string name, object value, RegistryValueKind valueKind)
 369                 {
 370                         AssertKeyStillValid ();
 371
 372                         if (value == null)
 373                                 throw new ArgumentNullException ("value");
 374
 375                         if (name != null)
 376                                 AssertKeyNameLength (name);
 377
 378                         if (!IsWritable)
 379                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 380
 381                         RegistryApi.SetValue (this, name, value, valueKind);
 382                 }
 383
 384                 /// <summary>
 385                 ///     Open the sub key specified, for read access.
 386                 /// </summary>
 387                 public RegistryKey OpenSubKey (string name)
 388                 {
 389                         return OpenSubKey (name, false);
 390                 }
 391
 392
 393                 /// <summary>
 394                 ///     Open the sub key specified.
 395                 /// </summary>
 396                 public RegistryKey OpenSubKey (string name, bool writable)
 397                 {
 398                         AssertKeyStillValid ();
 399
 400                         if (name == null)
 401                                 throw new ArgumentNullException ("name");
 402
 403                         AssertKeyNameLength (name);
 404
 405                         return RegistryApi.OpenSubKey (this, name, writable);
 406                 }
 407
 408
 409                 /// <summary>
 410                 ///     Get a registry value.
 411                 /// </summary>
 412                 public object GetValue (string name)
 413                 {
 414                         return GetValue (name, null);
 415                 }
 416
 417
 418                 /// <summary>
 419                 ///     Get a registry value.
 420                 /// </summary>
 421                 public object GetValue (string name, object defaultValue)
 422                 {
 423                         AssertKeyStillValid ();
 424
 425                         return RegistryApi.GetValue (this, name, defaultValue,
 426                                 RegistryValueOptions.None);
 427                 }
 428
 429                 [ComVisible (false)]
 430                 public object GetValue (string name, object defaultValue, RegistryValueOptions options)
 431                 {
 432                         AssertKeyStillValid ();
 433
 434                         return RegistryApi.GetValue (this, name, defaultValue, options);
 435                 }
 436
 437                 [ComVisible (false)]
 438                 public RegistryValueKind GetValueKind (string name)
 439                 {
 440                         return RegistryApi.GetValueKind (this, name);
 441                 }
 442
 443                 /// <summary>
 444                 ///     Create a sub key.
 445                 /// </summary>
 446                 public RegistryKey CreateSubKey (string subkey)
 447                 {
 448                         AssertKeyStillValid ();
 449                         AssertKeyNameNotNull (subkey);
 450                         AssertKeyNameLength (subkey);
 451
 452                         if (!IsWritable)
 453                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 454                         return RegistryApi.CreateSubKey (this, subkey);
 455                 }
 456
 457                 [ComVisible (false)]
 458                 [MonoLimitation ("permissionCheck is ignored in Mono")]
 459                 public RegistryKey CreateSubKey (string subkey, RegistryKeyPermissionCheck permissionCheck)
 460                 {
 461                         return CreateSubKey (subkey);
 462                 }
 463
 464                 [ComVisible (false)]
 465                 [MonoLimitation ("permissionCheck and registrySecurity are ignored in Mono")]
 466                 public RegistryKey CreateSubKey (string subkey, RegistryKeyPermissionCheck permissionCheck, RegistrySecurity registrySecurity)
 467                 {
 468                         return CreateSubKey (subkey);
 469                 }
 470
 471                 [ComVisible (false)]
 472                 [MonoLimitation ("permissionCheck is ignored in Mono")]
 473                 public RegistryKey CreateSubKey (string subkey, RegistryKeyPermissionCheck permissionCheck, RegistryOptions options)
 474                 {
 475                         AssertKeyStillValid ();
 476                         AssertKeyNameNotNull (subkey);
 477                         AssertKeyNameLength (subkey);
 478
 479                         if (!IsWritable)
 480                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 481
 482                         return RegistryApi.CreateSubKey (this, subkey, options);
 483                 }
 484
 485                 [ComVisible (false)]
 486                 [MonoLimitation ("permissionCheck and registrySecurity are ignored in Mono")]
 487                 public RegistryKey CreateSubKey (string subkey, RegistryKeyPermissionCheck permissionCheck, RegistryOptions registryOptions,
 488                         RegistrySecurity registrySecurity)
 489                 {
 490                         return CreateSubKey (subkey, permissionCheck, registryOptions);
 491                 }
 492
 493                 [ComVisible(false)]
 494                 public RegistryKey CreateSubKey (string subkey, bool writable)
 495                 {
 496                         return CreateSubKey (subkey, writable ? RegistryKeyPermissionCheck.ReadWriteSubTree : RegistryKeyPermissionCheck.ReadSubTree);
 497                 }
 498
 499                 [ComVisible(false)]
 500                 public RegistryKey CreateSubKey (string subkey, bool writable, RegistryOptions options)
 501                 {
 502                         return CreateSubKey (subkey, writable ? RegistryKeyPermissionCheck.ReadWriteSubTree : RegistryKeyPermissionCheck.ReadSubTree, options);
 503                 }
 504
 505                 /// <summary>
 506                 ///     Delete the specified subkey.
 507                 /// </summary>
 508                 public void DeleteSubKey(string subkey)
 509                 {
 510                         DeleteSubKey (subkey, true);
 511                 }
 512
 513
 514                 /// <summary>
 515                 ///     Delete the specified subkey.
 516                 /// </summary>
 517                 public void DeleteSubKey(string subkey, bool throwOnMissingSubKey)
 518                 {
 519                         AssertKeyStillValid ();
 520                         AssertKeyNameNotNull (subkey);
 521                         AssertKeyNameLength (subkey);
 522
 523                         if (!IsWritable)
 524                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 525
 526                         RegistryKey child = OpenSubKey (subkey);
 527
 528                         if (child == null) {
 529                                 if (throwOnMissingSubKey)
 530                                         throw new ArgumentException ("Cannot delete a subkey tree"
 531                                                 + " because the subkey does not exist.");
 532                                 return;
 533                         }
 534
 535                         if (child.SubKeyCount > 0){
 536                                 throw new InvalidOperationException ("Registry key has subkeys"
 537                                         + " and recursive removes are not supported by this method.");
 538                         }
 539
 540                         child.Close ();
 541
 542                         RegistryApi.DeleteKey (this, subkey, throwOnMissingSubKey);
 543                 }
 544
 545
 546                 /// <summary>
 547                 ///     Delete a sub tree (node, and values alike).
 548                 /// </summary>
 549                 public void DeleteSubKeyTree(string subkey)
 550                 {
 551                         DeleteSubKeyTree (subkey, true);
 552                 }
 553
 554                 public
 555                 void DeleteSubKeyTree (string subkey, bool throwOnMissingSubKey)
 556                 {
 557                         // Note: this is done by deleting sub-nodes recursively.
 558                         // The preformance is not very good. There may be a
 559                         // better way to implement this.
 560
 561                         AssertKeyStillValid ();
 562                         AssertKeyNameNotNull (subkey);
 563                         AssertKeyNameLength (subkey);
 564
 565                         RegistryKey child = OpenSubKey (subkey, true);
 566                         if (child == null) {
 567                                 if (!throwOnMissingSubKey)
 568                                         return;
 569
 570                                 throw new ArgumentException ("Cannot delete a subkey tree"
 571                                         + " because the subkey does not exist.");
 572                         }
 573
 574                         child.DeleteChildKeysAndValues ();
 575                         child.Close ();
 576                         DeleteSubKey (subkey, false);
 577                 }
 578
 579
 580                 /// <summary>
 581                 ///     Delete a value from the registry.
 582                 /// </summary>
 583                 public void DeleteValue(string name)
 584                 {
 585                         DeleteValue (name, true);
 586                 }
 587
 588
 589                 /// <summary>
 590                 ///     Delete a value from the registry.
 591                 /// </summary>
 592                 public void DeleteValue(string name, bool throwOnMissingValue)
 593                 {
 594                         AssertKeyStillValid ();
 595
 596                         if (name == null)
 597                                 throw new ArgumentNullException ("name");
 598
 599                         if (!IsWritable)
 600                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 601
 602                         RegistryApi.DeleteValue (this, name, throwOnMissingValue);
 603                 }
 604
 605                 public RegistrySecurity GetAccessControl ()
 606                 {
 607                         return GetAccessControl (AccessControlSections.Owner |
 608                                                  AccessControlSections.Group |
 609                                                  AccessControlSections.Access);
 610                 }
 611
 612                 public RegistrySecurity GetAccessControl (AccessControlSections includeSections)
 613                 {
 614                         return new RegistrySecurity (Name, includeSections);
 615                 }
 616
 617
 618                 /// <summary>
 619                 ///     Get the names of the sub keys.
 620                 /// </summary>
 621                 public string[] GetSubKeyNames()
 622                 {
 623                         AssertKeyStillValid ();
 624
 625                         return RegistryApi.GetSubKeyNames (this);
 626                 }
 627
 628
 629                 /// <summary>
 630                 ///     Get the names of values contained in this key.
 631                 /// </summary>
 632                 public string[] GetValueNames()
 633                 {
 634                         AssertKeyStillValid ();
 635                         return RegistryApi.GetValueNames (this);
 636                 }
 637
 638                 [ComVisible (false)]
 639                 [SecurityPermission (SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
 640                 [MonoTODO ("Not implemented on unix")]
 641                 public static RegistryKey FromHandle (SafeRegistryHandle handle)
 642                 {
 643                         if (handle == null)
 644                                 throw new ArgumentNullException ("handle");
 645
 646                         return RegistryApi.FromHandle (handle);
 647                 }
 648
 649                 [ComVisible (false)]
 650                 [SecurityPermission (SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
 651                 [MonoTODO ("Not implemented on unix")]
 652                 public static RegistryKey FromHandle (SafeRegistryHandle handle, RegistryView view)
 653                 {
 654                         return FromHandle (handle);
 655                 }
 656
 657
 658                 [MonoTODO ("Not implemented on unix")]
 659                 public static RegistryKey OpenRemoteBaseKey(RegistryHive hKey,string machineName)
 660                 {
 661                         if (machineName == null)
 662                                 throw new ArgumentNullException ("machineName");
 663                         return RegistryApi.OpenRemoteBaseKey (hKey, machineName);
 664                 }
 665
 666                 [ComVisible (false)]
 667                 [MonoTODO ("Not implemented on unix")]
 668                 public static RegistryKey OpenRemoteBaseKey (RegistryHive hKey, string machineName, RegistryView view)
 669                 {
 670                         if (machineName == null)
 671                                 throw new ArgumentNullException ("machineName");
 672                         return RegistryApi.OpenRemoteBaseKey (hKey, machineName);
 673                 }
 674
 675                 [ComVisible (false)]
 676                 [MonoLimitation ("View is ignored in Mono")]
 677                 public static RegistryKey OpenBaseKey (RegistryHive hKey, RegistryView view)
 678                 {
 679                         switch (hKey) {
 680                                 case RegistryHive.ClassesRoot:
 681                                         return Registry.ClassesRoot;
 682                                 case RegistryHive.CurrentConfig:
 683                                         return Registry.CurrentConfig;
 684                                 case RegistryHive.CurrentUser:
 685                                         return Registry.CurrentUser;
 686                                 case RegistryHive.DynData:
 687                                         return Registry.DynData;
 688                                 case RegistryHive.LocalMachine:
 689                                         return Registry.LocalMachine;
 690                                 case RegistryHive.PerformanceData:
 691                                         return Registry.PerformanceData;
 692                                 case RegistryHive.Users:
 693                                         return Registry.Users;
 694                         }
 695
 696                         throw new ArgumentException ("hKey");
 697                 }
 698
 699                 [ComVisible (false)]
 700                 public RegistryKey OpenSubKey (string name, RegistryKeyPermissionCheck permissionCheck)
 701                 {
 702                         return OpenSubKey (name, permissionCheck == RegistryKeyPermissionCheck.ReadWriteSubTree);
 703                 }
 704
 705                 [ComVisible (false)]
 706                 [MonoLimitation ("rights are ignored in Mono")]
 707                 public RegistryKey OpenSubKey (string name, RegistryRights rights)
 708                 {
 709                         return OpenSubKey (name);
 710                 }
 711
 712                 [ComVisible (false)]
 713                 [MonoLimitation ("rights are ignored in Mono")]
 714                 public RegistryKey OpenSubKey (string name, RegistryKeyPermissionCheck permissionCheck, RegistryRights rights)
 715                 {
 716                         return OpenSubKey (name, permissionCheck == RegistryKeyPermissionCheck.ReadWriteSubTree);
 717                 }
 718
 719                 public void SetAccessControl (RegistrySecurity registrySecurity)
 720                 {
 721                         if (null == registrySecurity)
 722                                 throw new ArgumentNullException ("registrySecurity");
 723
 724                         registrySecurity.PersistModifications (Name);
 725                 }
 726
 727
 728                 /// <summary>
 729                 ///     Build a string representation of the registry key.
 730                 ///     Conatins the fully qualified key name, and the Hex
 731                 ///     representation of the registry key handle.
 732                 /// </summary>
 733                 public override string ToString()
 734                 {
 735                         AssertKeyStillValid ();
 736
 737                         return RegistryApi.ToString (this);
 738                 }
 739
 740                 #endregion // PublicAPI
 741
 742                 internal bool IsRoot {
 743                         get { return hive != null; }
 744                 }
 745
 746                 private bool IsWritable {
 747                         get { return isWritable; }
 748                 }
 749
 750                 internal RegistryHive Hive {
 751                         get {
 752                                 if (!IsRoot)
 753                                         throw new NotSupportedException ();
 754                                 return (RegistryHive) hive;
 755                         }
 756                 }
 757
 758                 // returns the key handle for the win32 implementation and the
 759                 // KeyHandler for the unix implementation
 760                 internal object InternalHandle {
 761                         get { return handle; }
 762                 }
 763
 764                 /// <summary>
 765                 /// validate that the registry key handle is still usable.
 766                 /// </summary>
 767                 private void AssertKeyStillValid ()
 768                 {
 769                         if (handle == null)
 770                                 throw new ObjectDisposedException ("Microsoft.Win32.RegistryKey");
 771                 }
 772
 773
 774                 /// <summary>
 775                 /// validate that the registry key handle is still usable, and
 776                 /// that the 'subKeyName' is not null.
 777                 /// </summary>
 778                 private void AssertKeyNameNotNull (string subKeyName)
 779                 {
 780                         if (subKeyName == null)
 781                                 throw new ArgumentNullException ("name");
 782                 }
 783
 784                 private void AssertKeyNameLength (string name)
 785                 {
 786                         if (name.Length > 255)
 787                                 throw new ArgumentException ("Name of registry key cannot be greater than 255 characters");
 788                 }
 789
 790                 /// <summary>
 791                 ///     Utility method to delelte a key's sub keys and values.
 792                 ///     This method removes a level of indirection when deleting
 793                 ///     key node trees.
 794                 /// </summary>
 795                 private void DeleteChildKeysAndValues ()
 796                 {
 797                         if (IsRoot)
 798                                 return;
 799
 800                         string[] subKeys = GetSubKeyNames ();
 801                         foreach (string subKey in subKeys)
 802                         {
 803                                 RegistryKey sub = OpenSubKey (subKey, true);
 804                                 sub.DeleteChildKeysAndValues ();
 805                                 sub.Close ();
 806                                 DeleteSubKey (subKey, false);
 807                         }
 808
 809                         string[] values = GetValueNames ();
 810                         foreach (string value in values) {
 811                                 DeleteValue (value, false);
 812                         }
 813                 }
 814
 815                 /// <summary>
 816                 ///     decode a byte array as a string, and strip trailing nulls
 817                 /// </summary>
 818                 static internal string DecodeString (byte[] data)
 819                 {
 820                         string stringRep = Encoding.Unicode.GetString (data);
 821                         int idx = stringRep.IndexOf ('\0');
 822                         if (idx != -1)
 823                                 stringRep = stringRep.TrimEnd ('\0');
 824                         return stringRep;
 825                 }
 826
 827                 static internal IOException CreateMarkedForDeletionException ()
 828                 {
 829                         throw new IOException ("Illegal operation attempted on a"
 830                                 + " registry key that has been marked for deletion.");
 831                 }
 832
 833                 static string GetHiveName (RegistryHive hive)
 834                 {
 835                         switch (hive) {
 836                         case RegistryHive.ClassesRoot:
 837                                 return "HKEY_CLASSES_ROOT";
 838                         case RegistryHive.CurrentConfig:
 839                                 return "HKEY_CURRENT_CONFIG";
 840                         case RegistryHive.CurrentUser:
 841                                 return "HKEY_CURRENT_USER";
 842                         case RegistryHive.DynData:
 843                                 return "HKEY_DYN_DATA";
 844                         case RegistryHive.LocalMachine:
 845                                 return "HKEY_LOCAL_MACHINE";
 846                         case RegistryHive.PerformanceData:
 847                                 return "HKEY_PERFORMANCE_DATA";
 848                         case RegistryHive.Users:
 849                                 return "HKEY_USERS";
 850                         }
 851
 852                         throw new NotImplementedException (string.Format (
 853                                 "Registry hive '{0}' is not implemented.", hive.ToString ()));
 854                 }
 855
 856         }
 857 #endif
 858 }
 859