ArgumentValue.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 / ArgumentValue.cs / 1305376 / ArgumentValue.cs
                        

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

namespace System.Activities.Expressions 
{
    using System.Collections.Generic; 
    using System.Linq.Expressions; 
    using System.Runtime;
    using System.Windows.Markup; 

    public sealed class ArgumentValue : CodeActivity
    {
        RuntimeArgument targetArgument; 

        public ArgumentValue() 
        { 
        }
 
        public ArgumentValue(string argumentName)
        {
            this.ArgumentName = argumentName;
        } 

        public string ArgumentName 
        { 
            get;
            set; 
        }

        protected override void CacheMetadata(CodeActivityMetadata metadata)
        { 
            this.targetArgument = null;
 
            if (string.IsNullOrEmpty(this.ArgumentName)) 
            {
                metadata.AddValidationError(SR.ArgumentNameRequired); 
            }
            else
            {
                this.targetArgument = ActivityUtilities.FindArgument(this.ArgumentName, this); 

                if (this.targetArgument == null) 
                { 
                    metadata.AddValidationError(SR.ArgumentNotFound(this.ArgumentName));
                } 
                else if (!TypeHelper.AreTypesCompatible(this.targetArgument.Type, typeof(T)))
                {
                    metadata.AddValidationError(SR.ArgumentTypeMustBeCompatible(this.ArgumentName, this.targetArgument.Type, typeof(T)));
                } 
            }
        } 
 
        public override string ToString()
        { 
            if (!string.IsNullOrEmpty(this.ArgumentName))
            {
                return this.ArgumentName;
            } 

            return base.ToString(); 
        } 

        internal override bool TryGetValue(ActivityContext context, out T value) 
        {
            if (this.targetArgument == null)
            {
                throw FxTrace.Exception.AsError(new InvalidOperationException(SR.UnopenedActivitiesCannotBeExecuted(this.DisplayName))); 
            }
 
            try 
            {
                context.AllowChainedEnvironmentAccess = true; 
                value = context.GetValue(this.targetArgument);
            }
            finally
            { 
                context.AllowChainedEnvironmentAccess = false;
            } 
 
            return true;
        } 

        protected override T Execute(CodeActivityContext context)
        {
            return ExecuteWithTryGetValue(context); 
        }
    } 
} 

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

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