Code:
/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / Orcas / SP / 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
- PackageProperties.cs
- ProgressBar.cs
- AutomationElementIdentifiers.cs
- DBConnection.cs
- PolicyVersion.cs
- ADConnectionHelper.cs
- COSERVERINFO.cs
- DesignerDataSchemaClass.cs
- DataServiceResponse.cs
- MultiAsyncResult.cs
- SoapAttributes.cs
- HtmlInputFile.cs
- ArraySegment.cs
- SecurityDescriptor.cs
- ObjectDataSourceEventArgs.cs
- RequestCacheManager.cs
- VarRefManager.cs
- MessageSecurityVersionConverter.cs
- Utils.cs
- PageAsyncTaskManager.cs
- Solver.cs
- WpfPayload.cs
- Baml2006ReaderFrame.cs
- SqlCommandBuilder.cs
- _UriTypeConverter.cs
- XmlNodeList.cs
- DocumentPageHost.cs
- TextTabProperties.cs
- BamlTreeNode.cs
- TextShapeableCharacters.cs
- basecomparevalidator.cs
- NegotiateStream.cs
- CqlParser.cs
- PathFigureCollection.cs
- WindowsProgressbar.cs
- Regex.cs
- EmbeddedMailObject.cs
- XmlReflectionMember.cs
- UnsafeNativeMethods.cs
- ConfigurationSection.cs
- ToolStripSettings.cs
- QueryInterceptorAttribute.cs
- EpmCustomContentWriterNodeData.cs
- AccessDataSourceView.cs
- VideoDrawing.cs
- PerformanceCounterManager.cs
- PieceNameHelper.cs
- RewritingPass.cs
- Module.cs
- Native.cs
- VisualStateChangedEventArgs.cs
- TextTrailingCharacterEllipsis.cs
- RbTree.cs
- EnvelopedPkcs7.cs
- HyperLinkStyle.cs
- LayoutTableCell.cs
- IPAddressCollection.cs
- StylusPoint.cs
- TextServicesCompartment.cs
- Activity.cs
- EditingMode.cs
- FastEncoder.cs
- GregorianCalendarHelper.cs
- SafeNativeMethods.cs
- UmAlQuraCalendar.cs
- SocketConnection.cs
- CodeMemberEvent.cs
- CustomError.cs
- XhtmlBasicObjectListAdapter.cs
- FormsAuthenticationConfiguration.cs
- SpecialTypeDataContract.cs
- WebPermission.cs
- UniqueID.cs
- BaseDataList.cs
- EmptyEnumerable.cs
- HtmlTable.cs
- CqlGenerator.cs
- FileDetails.cs
- OutputScopeManager.cs
- EventMappingSettingsCollection.cs
- WebPartMenuStyle.cs
- ModelPropertyImpl.cs
- ControlAdapter.cs
- WebPartsPersonalizationAuthorization.cs
- TagMapInfo.cs
- FixedFindEngine.cs
- Assembly.cs
- XmlAnyAttributeAttribute.cs
- XsdBuildProvider.cs
- RequestFactory.cs
- XmlSchemaComplexType.cs
- TypeUsage.cs
- Path.cs
- SqlDataSourceCommandEventArgs.cs
- RSAPKCS1KeyExchangeDeformatter.cs
- CanExecuteRoutedEventArgs.cs
- WhitespaceSignificantCollectionAttribute.cs
- CommandBinding.cs
- BooleanSwitch.cs
- DependencyPropertyKey.cs