HandleScope.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 / Statements / HandleScope.cs / 1305376 / HandleScope.cs
                        

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

namespace System.Activities.Statements 
{
    using System.Activities; 
    using System.Collections.Generic; 
    using System.Collections.ObjectModel;
    using System.Runtime; 
    using System.Windows.Markup;

    [ContentProperty("Body")]
    public sealed class HandleScope : NativeActivity 
        where THandle : Handle
    { 
        Variable declaredHandle; 

        public HandleScope() 
        {
        }

        public InArgument Handle 
        {
            get; 
            set; 
        }
 
        public Activity Body
        {
            get;
            set; 
        }
 
        protected override void CacheMetadata(NativeActivityMetadata metadata) 
        {
            RuntimeArgument handleArgument = new RuntimeArgument("Handle", typeof(THandle), ArgumentDirection.In); 
            metadata.Bind(this.Handle, handleArgument);
            metadata.SetArgumentsCollection(new Collection { handleArgument });

            if (this.Body != null) 
            {
                metadata.SetChildrenCollection(new Collection { this.Body }); 
            } 

            Collection implementationVariables = null; 

            if ((this.Handle == null) || this.Handle.IsEmpty)
            {
                if (this.declaredHandle == null) 
                {
                    this.declaredHandle = new Variable(); 
                } 
            }
            else 
            {
                this.declaredHandle = null;
            }
 
            if (this.declaredHandle != null)
            { 
                ActivityUtilities.Add(ref implementationVariables, this.declaredHandle); 
            }
 
            metadata.SetImplementationVariablesCollection(implementationVariables);
        }

        protected override void Execute(NativeActivityContext context) 
        {
            // We should go through the motions even if there is no Body for debugging 
            // purposes.  When testing handles people will probably use empty scopes 
            // expecting everything except the Body execution to occur.
 
            Handle scopedHandle = null;

            if ((this.Handle == null) || this.Handle.IsEmpty)
            { 
                Fx.Assert(this.declaredHandle != null, "We should have declared the variable if we didn't have the argument set.");
                scopedHandle = this.declaredHandle.Get(context); 
            } 
            else
            { 
                scopedHandle = this.Handle.Get(context);
            }

            if (scopedHandle == null) 
            {
                throw FxTrace.Exception.ArgumentNull("Handle"); 
            } 

            context.Properties.Add(scopedHandle.ExecutionPropertyName, scopedHandle); 

            if (this.Body != null)
            {
                context.ScheduleActivity(this.Body); 
            }
        } 
    } 
}

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

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