Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / wpf / src / Core / CSharp / System / Windows / Media / Animation / WeakRefEnumerator.cs / 1 / WeakRefEnumerator.cs
//------------------------------------------------------------------------------ // Microsoft Windows Client Platform // Copyright (c) Microsoft Corporation, 2003 // // File: WeakRefEnumerator.cs //----------------------------------------------------------------------------- using System; using System.Collections.Generic; using System.Diagnostics; namespace System.Windows.Media.Animation { ////// An enumerator for collections of weak references. /// ////// The enumerator returns only live objects and removes dead /// references from the list as it walks. /// internal struct WeakRefEnumerator{ #region Internal implementation #region Construction /// /// Creates an enumerator for the given list. /// /// /// The list to enumerate. /// internal WeakRefEnumerator(Listlist) { _list = list; _readIndex = 0; _writeIndex = 0; _current = default(T); #if DEBUG _valid = false; #endif // DEBUG } #endregion // Construction #region Properties /// /// Gets the current element in the collection. /// ////// The current element in the collection. /// internal T Current { get { #if DEBUG Debug.Assert(_valid); #endif // DEBUG return _current; } } ////// Gets the index of the current element in the collection. /// ////// The index of the current element in the collection. /// internal int CurrentIndex { get { #if DEBUG Debug.Assert(_valid); #endif // DEBUG return _writeIndex - 1; } } #endregion // Properties #region Methods ////// This method must be called when the enumerator is no longer /// in use, if the last call to MoveNext returned true. The /// enumerator is no longer valid after this call. /// ////// When MoveNext returns false, the collection being enumerated is /// left in a good, known state, so nothing additional needs to be /// done. However, before MoveNext returns false the collection is /// in an intermediate state, so if the enumerator isn't advanced /// all the way to the end then this method must be called to clean /// up the collection and make sure that it ends in a known state. /// Calling this method in the case where MoveNext has returned /// false is OK. In that case, the method is a no-op. /// internal void Dispose() { // Remove only those elements that we've previously seen. // This means removing the range between the read and write // indices, as that's dead space in the collection. if (_readIndex != _writeIndex) { _list.RemoveRange(_writeIndex, _readIndex - _writeIndex); _readIndex = _writeIndex = _list.Count; } _current = default(T); #if DEBUG _valid = false; #endif // DEBUG } ////// Advances the enumerator to the next element of the collection. /// ////// true if the enumerator was successfully advanced to the next /// element; false if the enumerator has passed the end of the /// collection. /// ////// Elements that have been GC'ed are removed from the list. /// internal bool MoveNext() { // Get a reference to the next element that has not yet been // garbage-collected while (_readIndex < _list.Count) { WeakReference currentRef = _list[_readIndex]; _current = (T)currentRef.Target; if ( (object)_current != null) { // Found a live object. First compress the list, which // is necessary if we've previously seen GC'ed objects. if (_writeIndex != _readIndex) { _list[_writeIndex] = currentRef; } // Update internal state and return the found element _readIndex++; _writeIndex++; #if DEBUG _valid = true; #endif // DEBUG return true; } else { // This object was garbage-collected, so keep looking _readIndex++; } } // If we get here we didn't have any more live elements in the // collection, so we should return false. This is also a good // opportunity to clean up the list as necessary. Dispose(); return false; } #endregion // Methods #region Data private List_list; private T _current; private int _readIndex; private int _writeIndex; #if DEBUG private bool _valid; #endif // DEBUG #endregion // Data #endregion // Internal implementation } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //------------------------------------------------------------------------------ // Microsoft Windows Client Platform // Copyright (c) Microsoft Corporation, 2003 // // File: WeakRefEnumerator.cs //----------------------------------------------------------------------------- using System; using System.Collections.Generic; using System.Diagnostics; namespace System.Windows.Media.Animation { /// /// An enumerator for collections of weak references. /// ////// The enumerator returns only live objects and removes dead /// references from the list as it walks. /// internal struct WeakRefEnumerator{ #region Internal implementation #region Construction /// /// Creates an enumerator for the given list. /// /// /// The list to enumerate. /// internal WeakRefEnumerator(Listlist) { _list = list; _readIndex = 0; _writeIndex = 0; _current = default(T); #if DEBUG _valid = false; #endif // DEBUG } #endregion // Construction #region Properties /// /// Gets the current element in the collection. /// ////// The current element in the collection. /// internal T Current { get { #if DEBUG Debug.Assert(_valid); #endif // DEBUG return _current; } } ////// Gets the index of the current element in the collection. /// ////// The index of the current element in the collection. /// internal int CurrentIndex { get { #if DEBUG Debug.Assert(_valid); #endif // DEBUG return _writeIndex - 1; } } #endregion // Properties #region Methods ////// This method must be called when the enumerator is no longer /// in use, if the last call to MoveNext returned true. The /// enumerator is no longer valid after this call. /// ////// When MoveNext returns false, the collection being enumerated is /// left in a good, known state, so nothing additional needs to be /// done. However, before MoveNext returns false the collection is /// in an intermediate state, so if the enumerator isn't advanced /// all the way to the end then this method must be called to clean /// up the collection and make sure that it ends in a known state. /// Calling this method in the case where MoveNext has returned /// false is OK. In that case, the method is a no-op. /// internal void Dispose() { // Remove only those elements that we've previously seen. // This means removing the range between the read and write // indices, as that's dead space in the collection. if (_readIndex != _writeIndex) { _list.RemoveRange(_writeIndex, _readIndex - _writeIndex); _readIndex = _writeIndex = _list.Count; } _current = default(T); #if DEBUG _valid = false; #endif // DEBUG } ////// Advances the enumerator to the next element of the collection. /// ////// true if the enumerator was successfully advanced to the next /// element; false if the enumerator has passed the end of the /// collection. /// ////// Elements that have been GC'ed are removed from the list. /// internal bool MoveNext() { // Get a reference to the next element that has not yet been // garbage-collected while (_readIndex < _list.Count) { WeakReference currentRef = _list[_readIndex]; _current = (T)currentRef.Target; if ( (object)_current != null) { // Found a live object. First compress the list, which // is necessary if we've previously seen GC'ed objects. if (_writeIndex != _readIndex) { _list[_writeIndex] = currentRef; } // Update internal state and return the found element _readIndex++; _writeIndex++; #if DEBUG _valid = true; #endif // DEBUG return true; } else { // This object was garbage-collected, so keep looking _readIndex++; } } // If we get here we didn't have any more live elements in the // collection, so we should return false. This is also a good // opportunity to clean up the list as necessary. Dispose(); return false; } #endregion // Methods #region Data private List_list; private T _current; private int _readIndex; private int _writeIndex; #if DEBUG private bool _valid; #endif // DEBUG #endregion // Data #endregion // Internal implementation } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- PackageRelationshipSelector.cs
- AdornerHitTestResult.cs
- ManagementOptions.cs
- M3DUtil.cs
- RequiredFieldValidator.cs
- ToolStripSplitStackLayout.cs
- NativeMethods.cs
- NameValueSectionHandler.cs
- FontStretches.cs
- XmlSchemaIdentityConstraint.cs
- SrgsElementList.cs
- DataGridViewRowHeaderCell.cs
- Vector3DConverter.cs
- Message.cs
- PassportAuthenticationModule.cs
- Encoding.cs
- BoundColumn.cs
- InheritedPropertyChangedEventArgs.cs
- SqlConnectionFactory.cs
- SelectorItemAutomationPeer.cs
- OutputScopeManager.cs
- OleDbMetaDataFactory.cs
- DataGridViewDataErrorEventArgs.cs
- HashHelpers.cs
- PeerApplicationLaunchInfo.cs
- XmlElementList.cs
- _ListenerResponseStream.cs
- TriggerCollection.cs
- XPathNodeInfoAtom.cs
- ResourceContainer.cs
- XmlObjectSerializerWriteContext.cs
- Vector3DCollectionValueSerializer.cs
- RecordBuilder.cs
- Rules.cs
- ConstraintEnumerator.cs
- PipeStream.cs
- PeerToPeerException.cs
- _CommandStream.cs
- Pen.cs
- QilLoop.cs
- ExpressionTextBox.xaml.cs
- ToolBarOverflowPanel.cs
- WeakReferenceKey.cs
- WebProxyScriptElement.cs
- DependencyObjectPropertyDescriptor.cs
- StringConverter.cs
- Switch.cs
- FreezableDefaultValueFactory.cs
- ValidationSummary.cs
- SrgsSemanticInterpretationTag.cs
- ContainerUtilities.cs
- CriticalFinalizerObject.cs
- ActivityTypeResolver.xaml.cs
- X509CertificateRecipientServiceCredential.cs
- ProfileProvider.cs
- NameValueConfigurationCollection.cs
- ContainerControl.cs
- HyperLink.cs
- SHA1Managed.cs
- LinqMaximalSubtreeNominator.cs
- UnsafePeerToPeerMethods.cs
- ProvideValueServiceProvider.cs
- ColumnResult.cs
- ClientUtils.cs
- Control.cs
- ControlAdapter.cs
- BufferModesCollection.cs
- MDIWindowDialog.cs
- DataControlHelper.cs
- ThemeInfoAttribute.cs
- EmissiveMaterial.cs
- BorderGapMaskConverter.cs
- RowSpanVector.cs
- XmlWellformedWriter.cs
- ObjectTag.cs
- UIPermission.cs
- EmptyStringExpandableObjectConverter.cs
- MessageProperties.cs
- AtomMaterializer.cs
- PerformanceCounter.cs
- CachedBitmap.cs
- HiddenFieldPageStatePersister.cs
- UIntPtr.cs
- ControlEvent.cs
- AssemblyHash.cs
- XslNumber.cs
- LinqDataSourceUpdateEventArgs.cs
- MobileCategoryAttribute.cs
- StyleSheetDesigner.cs
- FragmentQueryKB.cs
- Rect.cs
- SafeRightsManagementSessionHandle.cs
- Main.cs
- InkPresenter.cs
- SelectionProviderWrapper.cs
- FamilyMap.cs
- HashUtility.cs
- FlowDocumentPaginator.cs
- ResourceCategoryAttribute.cs
- SQLDecimal.cs