Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / System.Activities / System / Activities / Expressions / Subtract.cs / 1305376 / Subtract.cs
//---------------------------------------------------------------- // Copyright (c) Microsoft Corporation. All rights reserved. //--------------------------------------------------------------- namespace System.Activities.Expressions { using System.Activities; using System.Activities.Statements; using System.Linq.Expressions; using System.Activities.Validation; using System.Collections.Generic; using System.ComponentModel; using System.Runtime; public sealed class Subtract: CodeActivity { //Lock is not needed for operationFunction here. The reason is that delegates for a given Subtract are the same. //It's possible that 2 threads are assigning the operationFucntion at the same time. But it's okay because the compiled codes are the same. static Func checkedOperationFunction; static Func uncheckedOperationFunction; bool checkedOperation = true; [RequiredArgument] [DefaultValue(null)] public InArgument Left { get; set; } [RequiredArgument] [DefaultValue(null)] public InArgument Right { get; set; } [DefaultValue(true)] public bool Checked { get { return this.checkedOperation; } set { this.checkedOperation = value; } } protected override void CacheMetadata(CodeActivityMetadata metadata) { BinaryExpressionHelper.OnGetArguments(metadata, this.Left, this.Right); if (this.checkedOperation) { EnsureOperationFunction(metadata, ref checkedOperationFunction, ExpressionType.SubtractChecked); } else { EnsureOperationFunction(metadata, ref uncheckedOperationFunction, ExpressionType.Subtract); } } void EnsureOperationFunction(CodeActivityMetadata metadata, ref Func operationFunction, ExpressionType operatorType) { if (operationFunction == null) { ValidationError validationError; if (!BinaryExpressionHelper.TryGenerateLinqDelegate( operatorType, out operationFunction, out validationError)) { metadata.AddValidationError(validationError); } } } protected override TResult Execute(CodeActivityContext context) { TLeft leftValue = this.Left.Get(context); TRight rightValue = this.Right.Get(context); //if user changed Checked flag between Open and Execution, //a NRE may be thrown and that's by design if (this.checkedOperation) { return checkedOperationFunction(leftValue, rightValue); } else { return uncheckedOperationFunction(leftValue, rightValue); } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- CallbackHandler.cs
- AddInActivator.cs
- EmptyReadOnlyDictionaryInternal.cs
- SqlReferenceCollection.cs
- LambdaCompiler.Expressions.cs
- TabItemWrapperAutomationPeer.cs
- PreservationFileWriter.cs
- CodeTryCatchFinallyStatement.cs
- RotationValidation.cs
- ListItemCollection.cs
- QilReference.cs
- DocumentCollection.cs
- SelectionRange.cs
- TextRangeSerialization.cs
- EventHandlersStore.cs
- CollectionDataContract.cs
- SessionStateItemCollection.cs
- AssemblyCache.cs
- SchemaDeclBase.cs
- TreeNodeStyle.cs
- CodeDOMUtility.cs
- SynchronizedDispatch.cs
- X509ChainPolicy.cs
- Domain.cs
- IPipelineRuntime.cs
- DataGridViewRowErrorTextNeededEventArgs.cs
- DataObjectCopyingEventArgs.cs
- DataBoundControlParameterTarget.cs
- TextDecorationCollectionConverter.cs
- WorkflowElementDialogWindow.xaml.cs
- ToReply.cs
- SecureConversationSecurityTokenParameters.cs
- webproxy.cs
- TemplateBaseAction.cs
- TableLayoutPanel.cs
- QilCloneVisitor.cs
- DataSysAttribute.cs
- PageCache.cs
- Crc32.cs
- baseshape.cs
- NetMsmqSecurity.cs
- ReferentialConstraint.cs
- FontResourceCache.cs
- SchemaNames.cs
- DetailsViewInsertedEventArgs.cs
- TextAnchor.cs
- ToolConsole.cs
- WebPartConnectionCollection.cs
- DebugView.cs
- ConfigUtil.cs
- RequestSecurityToken.cs
- TableDetailsRow.cs
- OutputCacheProfile.cs
- CursorConverter.cs
- RuleInfoComparer.cs
- DataGridViewBindingCompleteEventArgs.cs
- HwndTarget.cs
- CursorEditor.cs
- CodeCompiler.cs
- ProtocolsConfiguration.cs
- SimplePropertyEntry.cs
- EndOfStreamException.cs
- FlowLayoutPanelDesigner.cs
- ResourceDefaultValueAttribute.cs
- ProviderCommandInfoUtils.cs
- ItemCollectionEditor.cs
- SchemaCollectionCompiler.cs
- IHttpResponseInternal.cs
- ReaderWriterLock.cs
- PrintControllerWithStatusDialog.cs
- OleDbCommandBuilder.cs
- GenerateTemporaryTargetAssembly.cs
- Assert.cs
- CompilerScope.cs
- GenericTypeParameterBuilder.cs
- OleDbFactory.cs
- SynthesizerStateChangedEventArgs.cs
- HttpRuntime.cs
- IdentityHolder.cs
- FormattedTextSymbols.cs
- TriState.cs
- ContextMenuStrip.cs
- ActivityFunc.cs
- Descriptor.cs
- WrappedDispatcherException.cs
- _HelperAsyncResults.cs
- DataListDesigner.cs
- PropertyChangedEventArgs.cs
- ElementUtil.cs
- AlignmentYValidation.cs
- ServiceDurableInstance.cs
- XmlLinkedNode.cs
- SingleTagSectionHandler.cs
- RedirectionProxy.cs
- MSAAWinEventWrap.cs
- ObjectDataSource.cs
- DbQueryCommandTree.cs
- StandardCommands.cs
- ComponentCollection.cs
- WebServiceReceiveDesigner.cs