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
- InkCanvasAutomationPeer.cs
- Grammar.cs
- SmiXetterAccessMap.cs
- COM2ExtendedBrowsingHandler.cs
- FileLogRecordEnumerator.cs
- ToolStripDropDownItem.cs
- DesignerContextDescriptor.cs
- DriveInfo.cs
- BindingListCollectionView.cs
- ImageConverter.cs
- log.cs
- DiagnosticTrace.cs
- OperatingSystem.cs
- SoapRpcServiceAttribute.cs
- SmiConnection.cs
- PackageRelationship.cs
- AbstractDataSvcMapFileLoader.cs
- UnmanagedMemoryStream.cs
- Property.cs
- WebPartDisplayModeCancelEventArgs.cs
- MaterialGroup.cs
- WebConfigurationHost.cs
- SqlFacetAttribute.cs
- DataGridViewColumnTypeEditor.cs
- XmlSchemaComplexType.cs
- PenContext.cs
- XmlSchemaExternal.cs
- Transform.cs
- DataContractSerializerOperationBehavior.cs
- ObjectConverter.cs
- CodeNamespaceCollection.cs
- EntityContainer.cs
- ISAPIRuntime.cs
- FastEncoderWindow.cs
- TileModeValidation.cs
- WpfXamlType.cs
- PathSegmentCollection.cs
- PropertyGroupDescription.cs
- CrossAppDomainChannel.cs
- SynchronizationContext.cs
- WebExceptionStatus.cs
- AncillaryOps.cs
- ThicknessAnimationBase.cs
- ValidationError.cs
- precedingquery.cs
- TileBrush.cs
- DrawingContextWalker.cs
- WebPartHeaderCloseVerb.cs
- QilStrConcat.cs
- CommandID.cs
- Stackframe.cs
- ReferentialConstraint.cs
- WebPartCatalogAddVerb.cs
- TransactionInformation.cs
- MissingFieldException.cs
- EmptyCollection.cs
- SchemaType.cs
- InkPresenter.cs
- AssemblyBuilder.cs
- PermissionAttributes.cs
- SiteMapDataSourceView.cs
- DataGridViewCellStyle.cs
- ErrorWebPart.cs
- FormViewDesigner.cs
- commandenforcer.cs
- ConfigXmlCDataSection.cs
- AnnotationHighlightLayer.cs
- SuppressMessageAttribute.cs
- ParseNumbers.cs
- WorkflowInstanceAbortedRecord.cs
- QuestionEventArgs.cs
- DataObjectMethodAttribute.cs
- BaseValidator.cs
- ContextStaticAttribute.cs
- Switch.cs
- ObjectComplexPropertyMapping.cs
- Int32Animation.cs
- TextSpan.cs
- KeyedCollection.cs
- PropertyConverter.cs
- SqlDataSourceFilteringEventArgs.cs
- HostingEnvironment.cs
- DefaultBinder.cs
- NullRuntimeConfig.cs
- WebServiceFaultDesigner.cs
- ContextMenuStrip.cs
- _FtpControlStream.cs
- NativeMethods.cs
- ZoneIdentityPermission.cs
- SettingsSection.cs
- EntityDataSourceState.cs
- ISAPIApplicationHost.cs
- DirectoryLocalQuery.cs
- ItemsPresenter.cs
- CodeCastExpression.cs
- SizeF.cs
- ClientTargetCollection.cs
- DataPagerFieldCollection.cs
- StatusBarItem.cs
- LayoutUtils.cs