Not.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / System.Activities / System / Activities / Expressions / Not.cs / 1305376 / Not.cs
                        

                        
                            //---------------------------------------------------------------- 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//---------------------------------------------------------------

namespace System.Activities.Expressions 
{
    using System.Activities; 
    using System.Activities.Validation; 
    using System.ComponentModel;
    using System.Diagnostics.CodeAnalysis; 
    using System.Linq.Expressions;
    using System.Runtime;

    [SuppressMessage(FxCop.Category.Naming, FxCop.Rule.IdentifiersShouldNotMatchKeywords, 
        Justification = "Optimizing for XAML naming. VB imperative users will [] qualify (e.g. New [Not])")]
    public sealed class Not : CodeActivity 
    { 
        //Lock is not needed for operationFunction here. The reason is that delegates for a given Not 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 operationFunction;

        [RequiredArgument]
        [DefaultValue(null)] 
        public InArgument Operand
        { 
            get; 
            set;
        } 


        protected override void CacheMetadata(CodeActivityMetadata metadata)
        { 
            UnaryExpressionHelper.OnGetArguments(metadata, this.Operand);
 
            if (operationFunction == null) 
            {
                ValidationError validationError; 
                if (!UnaryExpressionHelper.TryGenerateLinqDelegate(ExpressionType.Not, out operationFunction, out validationError))
                {
                    metadata.AddValidationError(validationError);
                } 
            }
        } 
        protected override TResult Execute(CodeActivityContext context) 
        {
            Fx.Assert(operationFunction != null, "OperationFunction must exist."); 
            TOperand operandValue = this.Operand.Get(context);
            return operationFunction(operandValue);
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK