Code:
/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / wpf / src / Framework / MS / Internal / Data / DynamicValueConverter.cs / 1 / DynamicValueConverter.cs
//---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // Description: wrapper around default converter to dynamcially pick // and change value converters depending on changing source and target types // //--------------------------------------------------------------------------- using System; using System.Globalization; using System.Collections; using System.ComponentModel; using System.Reflection; using System.Windows; using System.Windows.Data; using MS.Internal; // Invariant.Assert using System.Diagnostics; namespace MS.Internal.Data { // dynamically pick and switch a default value converter to convert between source and target type internal class DynamicValueConverter : IValueConverter { internal DynamicValueConverter(bool targetToSourceNeeded) { _targetToSourceNeeded = targetToSourceNeeded; } internal DynamicValueConverter(bool targetToSourceNeeded, Type sourceType, Type targetType) { _targetToSourceNeeded = targetToSourceNeeded; EnsureConverter(sourceType, targetType); } internal object Convert(object value, Type targetType) { return Convert(value, targetType, null, CultureInfo.InvariantCulture); } public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { object result = DependencyProperty.UnsetValue; // meaning: failure to convert if (value != null) { Type sourceType = value.GetType(); EnsureConverter(sourceType, targetType); if (_converter != null) { result = _converter.Convert(value, targetType, parameter, culture); } } else { if (!targetType.IsValueType) { result = null; } } return result; } public object ConvertBack(object value, Type sourceType, object parameter, CultureInfo culture) { object result = DependencyProperty.UnsetValue; // meaning: failure to convert if (value != null) { Type targetType = value.GetType(); EnsureConverter(sourceType, targetType); if (_converter != null) { result = _converter.ConvertBack(value, sourceType, parameter, culture); } } else { if (!sourceType.IsValueType) { result = null; } } return result; } private void EnsureConverter(Type sourceType, Type targetType) { if ((_sourceType != sourceType) || (_targetType != targetType)) { // types have changed - get a new converter if (sourceType != null && targetType != null) { // DefaultValueConverter.Create() is more sophisticated to find correct type converters, // e.g. if source/targetType is object or well-known system types. // if there is any change in types, give that code to come up with the correct converter if (_engine == null) { _engine = DataBindEngine.CurrentDataBindEngine; } Invariant.Assert(_engine != null); _converter = _engine.GetDefaultValueConverter(sourceType, targetType, _targetToSourceNeeded); } else { // if either type is null, no conversion is possible. // Don't ask GetDefaultValueConverter - it will use null as a // hashtable key, and crash (bug 110859). _converter = null; } _sourceType = sourceType; _targetType = targetType; } } private Type _sourceType; private Type _targetType; private IValueConverter _converter; private bool _targetToSourceNeeded; private DataBindEngine _engine; } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // Description: wrapper around default converter to dynamcially pick // and change value converters depending on changing source and target types // //--------------------------------------------------------------------------- using System; using System.Globalization; using System.Collections; using System.ComponentModel; using System.Reflection; using System.Windows; using System.Windows.Data; using MS.Internal; // Invariant.Assert using System.Diagnostics; namespace MS.Internal.Data { // dynamically pick and switch a default value converter to convert between source and target type internal class DynamicValueConverter : IValueConverter { internal DynamicValueConverter(bool targetToSourceNeeded) { _targetToSourceNeeded = targetToSourceNeeded; } internal DynamicValueConverter(bool targetToSourceNeeded, Type sourceType, Type targetType) { _targetToSourceNeeded = targetToSourceNeeded; EnsureConverter(sourceType, targetType); } internal object Convert(object value, Type targetType) { return Convert(value, targetType, null, CultureInfo.InvariantCulture); } public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { object result = DependencyProperty.UnsetValue; // meaning: failure to convert if (value != null) { Type sourceType = value.GetType(); EnsureConverter(sourceType, targetType); if (_converter != null) { result = _converter.Convert(value, targetType, parameter, culture); } } else { if (!targetType.IsValueType) { result = null; } } return result; } public object ConvertBack(object value, Type sourceType, object parameter, CultureInfo culture) { object result = DependencyProperty.UnsetValue; // meaning: failure to convert if (value != null) { Type targetType = value.GetType(); EnsureConverter(sourceType, targetType); if (_converter != null) { result = _converter.ConvertBack(value, sourceType, parameter, culture); } } else { if (!sourceType.IsValueType) { result = null; } } return result; } private void EnsureConverter(Type sourceType, Type targetType) { if ((_sourceType != sourceType) || (_targetType != targetType)) { // types have changed - get a new converter if (sourceType != null && targetType != null) { // DefaultValueConverter.Create() is more sophisticated to find correct type converters, // e.g. if source/targetType is object or well-known system types. // if there is any change in types, give that code to come up with the correct converter if (_engine == null) { _engine = DataBindEngine.CurrentDataBindEngine; } Invariant.Assert(_engine != null); _converter = _engine.GetDefaultValueConverter(sourceType, targetType, _targetToSourceNeeded); } else { // if either type is null, no conversion is possible. // Don't ask GetDefaultValueConverter - it will use null as a // hashtable key, and crash (bug 110859). _converter = null; } _sourceType = sourceType; _targetType = targetType; } } private Type _sourceType; private Type _targetType; private IValueConverter _converter; private bool _targetToSourceNeeded; private DataBindEngine _engine; } } // 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
- RegexWorker.cs
- PropertyDescriptorCollection.cs
- BigInt.cs
- ReadOnlyAttribute.cs
- AttributeCollection.cs
- HMACSHA1.cs
- NativeMethods.cs
- CharacterHit.cs
- ConfigUtil.cs
- BamlCollectionHolder.cs
- DispatchOperation.cs
- RadialGradientBrush.cs
- TypeBuilderInstantiation.cs
- TreeView.cs
- RtfToXamlLexer.cs
- XmlSchemaException.cs
- TraceSection.cs
- PassportIdentity.cs
- MdImport.cs
- nulltextnavigator.cs
- WebPartAddingEventArgs.cs
- HMAC.cs
- ExeConfigurationFileMap.cs
- VBCodeProvider.cs
- UrlMapping.cs
- ISCIIEncoding.cs
- XPathNavigatorKeyComparer.cs
- ListViewAutomationPeer.cs
- SqlOuterApplyReducer.cs
- FormsAuthenticationUser.cs
- IpcClientChannel.cs
- DynamicQueryableWrapper.cs
- SchemaConstraints.cs
- XamlInt32CollectionSerializer.cs
- EntityDataSourceWrapperCollection.cs
- PasswordPropertyTextAttribute.cs
- LocatorBase.cs
- DrawingAttributesDefaultValueFactory.cs
- SafeHandles.cs
- SafeNativeMethods.cs
- UdpDuplexChannel.cs
- MenuItem.cs
- GridViewCellAutomationPeer.cs
- SqlRowUpdatedEvent.cs
- SqlFactory.cs
- CompModSwitches.cs
- SortedDictionary.cs
- AlignmentXValidation.cs
- PageBuildProvider.cs
- StorageEndPropertyMapping.cs
- AuthenticationService.cs
- ProgressBar.cs
- SimpleHandlerFactory.cs
- Comparer.cs
- WorkflowItemsPresenter.cs
- Connection.cs
- BindingsCollection.cs
- Marshal.cs
- OleDbWrapper.cs
- PreparingEnlistment.cs
- ColumnMapCopier.cs
- SharedDp.cs
- NetworkCredential.cs
- BitmapEffectRenderDataResource.cs
- TrustManager.cs
- TriState.cs
- MDIClient.cs
- BamlWriter.cs
- DebugTracing.cs
- BaseCollection.cs
- WaitHandleCannotBeOpenedException.cs
- EntityAdapter.cs
- XmlIterators.cs
- XmlSchemaSimpleContent.cs
- ExtensionQuery.cs
- InputReportEventArgs.cs
- TextFormatterContext.cs
- CustomValidator.cs
- SecureUICommand.cs
- OrderedDictionary.cs
- XamlFigureLengthSerializer.cs
- ConstrainedGroup.cs
- RegexInterpreter.cs
- ConfigurationStrings.cs
- UserControlAutomationPeer.cs
- ObjectIDGenerator.cs
- WebPartVerb.cs
- AuthenticationServiceManager.cs
- WebZone.cs
- PromptBuilder.cs
- LeafCellTreeNode.cs
- ToolStripRendererSwitcher.cs
- OptimisticConcurrencyException.cs
- EventKeyword.cs
- ConvertBinder.cs
- SecurityCapabilities.cs
- DataComponentNameHandler.cs
- FontWeight.cs
- TrustLevel.cs
- sqlpipe.cs