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
  40 namespace Microsoft.Win32
  41 {
  42         /// <summary>
  43         ///     Wrapper class for Windows Registry Entry.
  44         /// </summary>
  45         public sealed class RegistryKey : MarshalByRefObject, IDisposable
  46         {
  47                 //
  48                 // This represents the backend data, used when creating the
  49                 // RegistryKey object
  50                 //
  51                 object handle;
  52
  53                 object hive; // the RegistryHive if the key represents a base key
  54                 readonly string qname;  // the fully qualified registry key name
  55                 readonly bool isRemoteRoot;     // is an instance of a remote root key?
  56                 readonly bool isWritable;       // is the key openen in writable mode
  57
  58                 static readonly IRegistryApi RegistryApi;
  59
  60                 static RegistryKey ()
  61                 {
  62                         if (Path.DirectorySeparatorChar == '\\')
  63                                 RegistryApi = new Win32RegistryApi ();
  64                         else
  65                                 RegistryApi = new UnixRegistryApi ();
  66                 }
  67
  68                 /// <summary>
  69                 ///     Construct an instance of a root registry key entry.
  70                 /// </summary>
  71                 internal RegistryKey (RegistryHive hiveId) : this (hiveId,
  72                         new IntPtr ((int) hiveId), false)
  73                 {
  74                 }
  75
  76                 /// <summary>
  77                 ///     Construct an instance of a root registry key entry.
  78                 /// </summary>
  79                 internal RegistryKey (RegistryHive hiveId, IntPtr keyHandle, bool remoteRoot)
  80                 {
  81                         hive = hiveId;
  82                         handle = keyHandle;
  83                         qname = GetHiveName (hiveId);
  84                         isRemoteRoot = remoteRoot;
  85                         isWritable = true; // always consider root writable
  86                 }
  87
  88                 /// <summary>
  89                 ///     Construct an instance of a registry key entry.
  90                 /// </summary>
  91                 internal RegistryKey (object data, string keyName, bool writable)
  92                 {
  93                         handle = data;
  94                         qname = keyName;
  95                         isWritable = writable;
  96                 }
  97
  98                 #region PublicAPI
  99
 100                 /// <summary>
 101                 ///     Dispose of registry key object. Close the
 102                 ///     key if it's still open.
 103                 /// </summary>
 104                 void IDisposable.Dispose ()
 105                 {
 106                         GC.SuppressFinalize (this);
 107                         Close ();
 108                 }
 109
 110
 111                 /// <summary>
 112                 ///     Final cleanup of registry key object. Close the
 113                 ///     key if it's still open.
 114                 /// </summary>
 115                 ~RegistryKey ()
 116                 {
 117                         Close ();
 118                 }
 119
 120
 121                 /// <summary>
 122                 ///     Get the fully qualified registry key name.
 123                 /// </summary>
 124                 public string Name {
 125                         get { return qname; }
 126                 }
 127
 128
 129                 /// <summary>
 130                 ///     Flush the current registry state to disk.
 131                 /// </summary>
 132                 public void Flush()
 133                 {
 134                         RegistryApi.Flush (this);
 135                 }
 136
 137
 138                 /// <summary>
 139                 ///     Close the current registry key and flushes the state of the registry
 140                 /// right away.
 141                 /// </summary>
 142                 public void Close()
 143                 {
 144                         Flush ();
 145
 146                         // a handle to a remote hive must be closed, while one to a local
 147                         // hive should not be closed
 148                         if (!isRemoteRoot && IsRoot)
 149                                 return;
 150
 151                         RegistryApi.Close (this);
 152                         handle = null;
 153                 }
 154
 155
 156                 /// <summary>
 157                 ///     get the number of sub-keys for this key
 158                 /// </summary>
 159                 public int SubKeyCount {
 160                         get {
 161                                 AssertKeyStillValid ();
 162
 163                                 return RegistryApi.SubKeyCount (this);
 164                         }
 165                 }
 166
 167
 168                 /// <summary>
 169                 ///     get the number of values for this key
 170                 /// </summary>
 171                 public int ValueCount {
 172                         get {
 173                                 AssertKeyStillValid ();
 174
 175                                 return RegistryApi.ValueCount (this);
 176                         }
 177                 }
 178
 179
 180                 /// <summary>
 181                 ///     Set a registry value.
 182                 /// </summary>
 183                 public void SetValue (string name, object value)
 184                 {
 185                         AssertKeyStillValid ();
 186
 187                         if (value == null)
 188                                 throw new ArgumentNullException ("value");
 189
 190                         if (!IsWritable)
 191                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 192
 193                         RegistryApi.SetValue (this, name, value);
 194                 }
 195
 196 #if NET_2_0
 197                 [ComVisible (false)]
 198                 public void SetValue (string name, object value, RegistryValueKind valueKind)
 199                 {
 200                         AssertKeyStillValid ();
 201
 202                         if (value == null)
 203                                 throw new ArgumentNullException ();
 204
 205                         if (!IsWritable)
 206                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 207
 208                         RegistryApi.SetValue (this, name, value, valueKind);
 209                 }
 210 #endif
 211
 212                 /// <summary>
 213                 ///     Open the sub key specified, for read access.
 214                 /// </summary>
 215                 public RegistryKey OpenSubKey (string keyName)
 216                 {
 217                         return OpenSubKey (keyName, false);
 218                 }
 219
 220
 221                 /// <summary>
 222                 ///     Open the sub key specified.
 223                 /// </summary>
 224                 public RegistryKey OpenSubKey (string keyName, bool writtable)
 225                 {
 226                         AssertKeyStillValid ();
 227                         AssertKeyNameNotNull (keyName);
 228
 229                         return RegistryApi.OpenSubKey (this, keyName, writtable);
 230                 }
 231
 232
 233                 /// <summary>
 234                 ///     Get a registry value.
 235                 /// </summary>
 236                 public object GetValue (string name)
 237                 {
 238                         return GetValue (name, null);
 239                 }
 240
 241
 242                 /// <summary>
 243                 ///     Get a registry value.
 244                 /// </summary>
 245                 public object GetValue (string name, object defaultValue)
 246                 {
 247                         AssertKeyStillValid ();
 248
 249                         return RegistryApi.GetValue (this, name, defaultValue,
 250                                 RegistryValueOptions.None);
 251                 }
 252
 253 #if NET_2_0
 254                 [ComVisible (false)]
 255                 public object GetValue (string name, object defaultValue, RegistryValueOptions options)
 256                 {
 257                         AssertKeyStillValid ();
 258
 259                         return RegistryApi.GetValue (this, name, defaultValue, options);
 260                 }
 261 #endif
 262
 263                 /// <summary>
 264                 ///     Create a sub key.
 265                 /// </summary>
 266                 public RegistryKey CreateSubKey (string subkey)
 267                 {
 268                         AssertKeyStillValid ();
 269                         AssertKeyNameNotNull (subkey);
 270                         if (subkey.Length > 255)
 271                                 throw new ArgumentException ("keyName length is larger than 255 characters", subkey);
 272
 273                         if (!IsWritable)
 274                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 275                         return RegistryApi.CreateSubKey (this, subkey);
 276                 }
 277
 278
 279                 /// <summary>
 280                 ///     Delete the specified subkey.
 281                 /// </summary>
 282                 public void DeleteSubKey(string subkey)
 283                 {
 284                         DeleteSubKey (subkey, true);
 285                 }
 286
 287
 288                 /// <summary>
 289                 ///     Delete the specified subkey.
 290                 /// </summary>
 291                 public void DeleteSubKey(string subkey, bool throwOnMissingSubKey)
 292                 {
 293                         AssertKeyStillValid ();
 294                         AssertKeyNameNotNull (subkey);
 295
 296                         if (!IsWritable)
 297                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 298
 299                         RegistryKey child = OpenSubKey (subkey);
 300
 301                         if (child == null) {
 302                                 if (throwOnMissingSubKey)
 303                                         throw new ArgumentException ("Cannot delete a subkey tree"
 304                                                 + " because the subkey does not exist.");
 305                                 return;
 306                         }
 307
 308                         if (child.SubKeyCount > 0){
 309                                 throw new InvalidOperationException ("Registry key has subkeys"
 310                                         + " and recursive removes are not supported by this method.");
 311                         }
 312
 313                         child.Close ();
 314
 315                         RegistryApi.DeleteKey (this, subkey, throwOnMissingSubKey);
 316                 }
 317
 318
 319                 /// <summary>
 320                 ///     Delete a sub tree (node, and values alike).
 321                 /// </summary>
 322                 public void DeleteSubKeyTree(string keyName)
 323                 {
 324                         // Note: this is done by deleting sub-nodes recursively.
 325                         // The preformance is not very good. There may be a
 326                         // better way to implement this.
 327
 328                         AssertKeyStillValid ();
 329                         AssertKeyNameNotNull (keyName);
 330
 331                         RegistryKey child = OpenSubKey (keyName, true);
 332                         if (child == null)
 333                                 throw new ArgumentException ("Cannot delete a subkey tree"
 334                                         + " because the subkey does not exist.");
 335
 336                         child.DeleteChildKeysAndValues ();
 337                         child.Close ();
 338                         DeleteSubKey (keyName, false);
 339                 }
 340
 341
 342                 /// <summary>
 343                 ///     Delete a value from the registry.
 344                 /// </summary>
 345                 public void DeleteValue(string value)
 346                 {
 347                         DeleteValue (value, true);
 348                 }
 349
 350
 351                 /// <summary>
 352                 ///     Delete a value from the registry.
 353                 /// </summary>
 354                 public void DeleteValue(string value, bool shouldThrowWhenKeyMissing)
 355                 {
 356                         AssertKeyStillValid ();
 357                         AssertKeyNameNotNull (value);
 358
 359                         if (!IsWritable)
 360                                 throw new UnauthorizedAccessException ("Cannot write to the registry key.");
 361
 362                         RegistryApi.DeleteValue (this, value, shouldThrowWhenKeyMissing);
 363                 }
 364
 365
 366                 /// <summary>
 367                 ///     Get the names of the sub keys.
 368                 /// </summary>
 369                 public string[] GetSubKeyNames()
 370                 {
 371                         AssertKeyStillValid ();
 372
 373                         return RegistryApi.GetSubKeyNames (this);
 374                 }
 375
 376
 377                 /// <summary>
 378                 ///     Get the names of values contained in this key.
 379                 /// </summary>
 380                 public string[] GetValueNames()
 381                 {
 382                         AssertKeyStillValid ();
 383                         return RegistryApi.GetValueNames (this);
 384                 }
 385
 386
 387                 [MonoTODO ("Not implemented on unix")]
 388                 public static RegistryKey OpenRemoteBaseKey(RegistryHive hKey,string machineName)
 389                 {
 390                         if (machineName == null)
 391                                 throw new ArgumentNullException ("machineName");
 392                         return RegistryApi.OpenRemoteBaseKey (hKey, machineName);
 393                 }
 394
 395
 396                 /// <summary>
 397                 ///     Build a string representation of the registry key.
 398                 ///     Conatins the fully qualified key name, and the Hex
 399                 ///     representation of the registry key handle.
 400                 /// </summary>
 401                 public override string ToString()
 402                 {
 403                         AssertKeyStillValid ();
 404
 405                         return RegistryApi.ToString (this);
 406                 }
 407
 408                 #endregion // PublicAPI
 409
 410                 internal bool IsRoot {
 411                         get { return hive != null; }
 412                 }
 413
 414                 private bool IsWritable {
 415                         get { return isWritable; }
 416                 }
 417
 418                 internal RegistryHive Hive {
 419                         get {
 420                                 if (!IsRoot)
 421                                         throw new NotSupportedException ();
 422                                 return (RegistryHive) hive;
 423                         }
 424                 }
 425
 426                 // returns the key handle for the win32 implementation and the
 427                 // KeyHandler for the unix implementation
 428                 internal object Handle {
 429                         get { return handle; }
 430                 }
 431
 432                 /// <summary>
 433                 /// validate that the registry key handle is still usable.
 434                 /// </summary>
 435                 private void AssertKeyStillValid ()
 436                 {
 437                         if (handle == null)
 438                                 throw new ObjectDisposedException ("Microsoft.Win32.RegistryKey");
 439                 }
 440
 441
 442                 /// <summary>
 443                 /// validate that the registry key handle is still usable, and
 444                 /// that the 'subKeyName' is not null.
 445                 /// </summary>
 446                 private void AssertKeyNameNotNull (string subKeyName)
 447                 {
 448                         if (subKeyName == null)
 449                                 throw new ArgumentNullException ();
 450                 }
 451
 452
 453                 /// <summary>
 454                 ///     Utility method to delelte a key's sub keys and values.
 455                 ///     This method removes a level of indirection when deleting
 456                 ///     key node trees.
 457                 /// </summary>
 458                 private void DeleteChildKeysAndValues ()
 459                 {
 460                         if (IsRoot)
 461                                 return;
 462
 463                         string[] subKeys = GetSubKeyNames ();
 464                         foreach (string subKey in subKeys)
 465                         {
 466                                 RegistryKey sub = OpenSubKey (subKey, true);
 467                                 sub.DeleteChildKeysAndValues ();
 468                                 sub.Close ();
 469                                 DeleteSubKey (subKey, false);
 470                         }
 471
 472                         string[] values = GetValueNames ();
 473                         foreach (string value in values) {
 474                                 DeleteValue (value, false);
 475                         }
 476                 }
 477
 478                 /// <summary>
 479                 ///     decode a byte array as a string, and strip trailing nulls
 480                 /// </summary>
 481                 static internal string DecodeString (byte[] data)
 482                 {
 483                         string stringRep = Encoding.Unicode.GetString (data);
 484                         int idx = stringRep.IndexOf ('\0');
 485                         if (idx != -1)
 486                                 stringRep = stringRep.TrimEnd ('\0');
 487                         return stringRep;
 488                 }
 489
 490                 static internal IOException CreateMarkedForDeletionException ()
 491                 {
 492                         throw new IOException ("Illegal operation attempted on a"
 493                                 + " registry key that has been marked for deletion.");
 494                 }
 495
 496                 static string GetHiveName (RegistryHive hive)
 497                 {
 498                         switch (hive) {
 499                         case RegistryHive.ClassesRoot:
 500                                 return "HKEY_CLASSES_ROOT";
 501                         case RegistryHive.CurrentConfig:
 502                                 return "HKEY_CURRENT_CONFIG";
 503                         case RegistryHive.CurrentUser:
 504                                 return "HKEY_CURRENT_USER";
 505                         case RegistryHive.DynData:
 506                                 return "HKEY_DYN_DATA";
 507                         case RegistryHive.LocalMachine:
 508                                 return "HKEY_LOCAL_MACHINE";
 509                         case RegistryHive.PerformanceData:
 510                                 return "HKEY_PERFORMANCE_DATA";
 511                         case RegistryHive.Users:
 512                                 return "HKEY_USERS";
 513                         }
 514
 515                         throw new NotImplementedException (string.Format (
 516                                 "Registry hive '{0}' is not implemented.", hive.ToString ()));
 517                 }
 518
 519         }
 520 }
 521