FtpWebRequest.EndGetRequestStream(IAsyncResult) Method
Definition
Important
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Ends a pending asynchronous operation started with BeginGetRequestStream(AsyncCallback, Object).
public:
override System::IO::Stream ^ EndGetRequestStream(IAsyncResult ^ asyncResult);public override System.IO.Stream EndGetRequestStream (IAsyncResult asyncResult);override this.EndGetRequestStream : IAsyncResult -> System.IO.StreamPublic Overrides Function EndGetRequestStream (asyncResult As IAsyncResult) As StreamParameters
- asyncResult
- IAsyncResult
The IAsyncResult object that was returned when the operation started.
Returns
A writable Stream instance associated with this instance.
Exceptions
asyncResult is null.
asyncResult was not obtained by calling BeginGetRequestStream(AsyncCallback, Object).
This method was already called for the operation identified by asyncResult.
Examples
The following code example demonstrates ending an asynchronous operation to get a request's stream. This code example is part of a larger example provided for the FtpWebRequest class overview.
private:
static void EndGetStreamCallback( IAsyncResult^ ar )
{
FtpState^ state = dynamic_cast<FtpState^>(ar->AsyncState);
Stream^ requestStream = nullptr;
// End the asynchronous call to get the request stream.
try
{
requestStream = state->Request->EndGetRequestStream( ar );
// Copy the file contents to the request stream.
const int bufferLength = 2048;
array<Byte>^buffer = gcnew array<Byte>(bufferLength);
int count = 0;
int readBytes = 0;
FileStream^ stream = File::OpenRead( state->FileName );
do
{
readBytes = stream->Read( buffer, 0, bufferLength );
requestStream->Write( buffer, 0, bufferLength );
count += readBytes;
}
while ( readBytes != 0 );
Console::WriteLine( "Writing {0} bytes to the stream.", count );
// IMPORTANT: Close the request stream before sending the request.
requestStream->Close();
// Asynchronously get the response to the upload request.
state->Request->BeginGetResponse( gcnew AsyncCallback( EndGetResponseCallback ), state );
}
// Return exceptions to the main application thread.
catch ( Exception^ e )
{
Console::WriteLine( "Could not get the request stream." );
state->OperationException = e;
state->OperationComplete->Set();
return;
}
}
private static void EndGetStreamCallback(IAsyncResult ar)
{
FtpState state = (FtpState) ar.AsyncState;
Stream requestStream = null;
// End the asynchronous call to get the request stream.
try
{
requestStream = state.Request.EndGetRequestStream(ar);
// Copy the file contents to the request stream.
const int bufferLength = 2048;
byte[] buffer = new byte[bufferLength];
int count = 0;
int readBytes = 0;
FileStream stream = File.OpenRead(state.FileName);
do
{
readBytes = stream.Read(buffer, 0, bufferLength);
requestStream.Write(buffer, 0, readBytes);
count += readBytes;
}
while (readBytes != 0);
Console.WriteLine ("Writing {0} bytes to the stream.", count);
// IMPORTANT: Close the request stream before sending the request.
requestStream.Close();
// Asynchronously get the response to the upload request.
state.Request.BeginGetResponse(
new AsyncCallback (EndGetResponseCallback),
state
);
}
// Return exceptions to the main application thread.
catch (Exception e)
{
Console.WriteLine("Could not get the request stream.");
state.OperationException = e;
state.OperationComplete.Set();
return;
}
}
Remarks
If the operation has not completed, the EndGetRequestStream method blocks until the operation completes. To determine whether the operation has completed, check the IsCompleted property before calling EndGetRequestStream.
In addition to the exceptions noted in "Exceptions," EndGetRequestStream rethrows exceptions that were thrown while opening the stream for writing.
Note
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in the .NET Framework.
