UIAgentAsyncEndRequest.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ WCF / WCF / 3.5.30729.1 / untmp / Orcas / SP / ndp / cdf / src / WCF / infocard / Service / managed / Microsoft / InfoCards / UIAgentAsyncEndRequest.cs / 1 / UIAgentAsyncEndRequest.cs

                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------
namespace Microsoft.InfoCards
{ 
    using System;
    using System.Collections; 
    using System.Diagnostics; 
    using System.Runtime.InteropServices;
    using System.Text; 
    using System.IO;
    using IDT = Microsoft.InfoCards.Diagnostics.InfoCardTrace;

    // 
    // Summary:
    //  Base class for all Async Completation requests from the UI Agent. 
    //  !!!!!! Subclasses should not override OnMarshalOutArgs. !!!!!!! 
    //
    internal abstract class UIAgentAsyncEndRequest : UIAgentRequest 
    {
        int     m_asyncHandle;
        bool    m_isCompleted;
        object  m_result; 
        bool    m_isCancelled;
 
        // 
        // Summary:
        //  Creates an new UIAgentAsyncEndRequest 
        //
        // Arguments:
        //  rpcHandle:  The RPC Context handle.
        //  inArgs:     The stream to hold the input arguments 
        //  outArgs:    The stream to hold the output arguments
        //  parent:     the parent UI Request 
        // 
        public UIAgentAsyncEndRequest(
                                IntPtr rpcHandle, 
                                Stream inArgs,
                                Stream outArgs,
                                ClientUIRequest parent )
            : base( rpcHandle, inArgs, outArgs, parent ) 
        {
        } 
 
        public object Result
        { 
            get
            {
                IDT.Assert( true == m_isCompleted, "Attempt to pick up async result before completion." );
                return m_result; 
            }
        } 
 
        public bool IsCancelled
        { 
            get
            {
                IDT.Assert( true == m_isCompleted, "Attempt to pick up async result before completion." );
                return m_isCancelled; 
            }
        } 
 

        // 
        // Summary:
        //  Read any inbound arguments.
        //
        // Remarks: 
        //  read the async context handle we send at the end of the Begin call.
        // 
        protected override void OnMarshalInArgs() 
        {
            BinaryReader breader = new InfoCardBinaryReader( InArgs, Encoding.Unicode ); 

            m_asyncHandle = breader.ReadInt32();

            IDT.Assert( 0 != m_asyncHandle, "null async handle" ); 
        }
 
        // 
        // Summary:
        //  Process the request, and wait for the async operation to complete or be canceled. 
        //
        protected override void OnProcess()
        {
            // 
            // Look up this Async operation on the parent request and wait for completion.  Return any errors by
            // throwing the exception. 
            // 
            //
            // In current implementation, if WaitForAsyncCompletion throws an exception 
            // then no asyncResult is returned, so it is not disposed off by the using statement.
            //
            using ( RpcAsyncResult asyncResult = ParentRequest.WaitForAsyncCompletion( m_asyncHandle ) )
            { 
                m_isCancelled = asyncResult.IsCanceled;
 
                if ( !m_isCancelled ) 
                {
                    m_result = asyncResult.Result; 
                }
            }

            m_isCompleted = true; 
        }
 
        // 
        // Summary:
        // This method determines whether the operation was cancelled or not, writes the appropriate indicator, and 
        // then calls OnMarshalAsyncOutArgs if appropriate.
        //
        protected sealed override void OnMarshalOutArgs()
        { 
            BinaryWriter writer = new BinaryWriter( OutArgs, Encoding.Unicode );
 
            writer.Write( IsCancelled ); 

            if ( !IsCancelled ) 
            {
                OnMarshalAsyncOutArgs( writer );
            }
        } 

        // 
        // Summary: 
        // This is called if the Async operation is not cancelled.
        // 
        protected virtual void OnMarshalAsyncOutArgs( BinaryWriter writer )
        {
            //
            // Default is to do nothing. 
            //
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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