NegotiateStream.EndRead(IAsyncResult) Method
Definition
Important
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Ends an asynchronous read operation that was started with a call to BeginRead(Byte[], Int32, Int32, AsyncCallback, Object).
public:
override int EndRead(IAsyncResult ^ asyncResult);
public override int EndRead (IAsyncResult asyncResult);
override this.EndRead : IAsyncResult -> int
Public Overrides Function EndRead (asyncResult As IAsyncResult) As Integer
Parameters
- asyncResult
- IAsyncResult
An IAsyncResult instance returned by a call to BeginRead(Byte[], Int32, Int32, AsyncCallback, Object).
Returns
A Int32 value that specifies the number of bytes read from the underlying stream.
Exceptions
asyncResult
is null
.
The asyncResult was not created by a call to BeginRead(Byte[], Int32, Int32, AsyncCallback, Object).
There is no pending read operation to complete.
-or-
Authentication has not occurred.
The read operation failed.
Examples
The following code example demonstrates ending an asynchronous read operation. For an example that demonstrates starting the operation, see BeginRead.
static void EndReadCallback( IAsyncResult^ ar )
{
// Get the saved data.
ClientState^ cState = dynamic_cast<ClientState^>(ar->AsyncState);
TcpClient^ clientRequest = cState->Client;
NegotiateStream^ authStream = dynamic_cast<NegotiateStream^>(cState->AuthStream);
// Get the buffer that stores the message sent by the client.
int bytes = -1;
// Read the client message.
try
{
bytes = authStream->EndRead( ar );
cState->Message->Append( Encoding::UTF8->GetChars( cState->Buffer, 0, bytes ) );
if ( bytes != 0 )
{
authStream->BeginRead( cState->Buffer, 0, cState->Buffer->Length, gcnew AsyncCallback( EndReadCallback ), cState );
return;
}
}
catch ( Exception^ e )
{
// A real application should do something
// useful here, such as logging the failure.
Console::WriteLine( L"Client message exception:" );
Console::WriteLine( e );
cState->Waiter->Set();
return;
}
IIdentity^ id = authStream->RemoteIdentity;
Console::WriteLine( L"{0} says {1}", id->Name, cState->Message );
cState->Waiter->Set();
}
private static void EndReadCallback(ClientState cState, int bytes)
{
NegotiateStream authStream = (NegotiateStream)cState.AuthenticatedStream;
// Read the client message.
try
{
cState.Message.Append(Encoding.UTF8.GetChars(cState.Buffer, 0, bytes));
if (bytes != 0)
{
Task<int> readTask = authStream.ReadAsync(cState.Buffer, 0, cState.Buffer.Length);
readTask
.ContinueWith(task => { EndReadCallback(cState, task.Result); })
.Wait();
return;
}
}
catch (Exception e)
{
// A real application should do something
// useful here, such as logging the failure.
Console.WriteLine("Client message exception:");
Console.WriteLine(e);
return;
}
IIdentity id = authStream.RemoteIdentity;
Console.WriteLine("{0} says {1}", id.Name, cState.Message.ToString());
}
Remarks
If the operation has not completed, this method blocks until it does.
To perform this operation synchronously, use the Read method.
You cannot call this method until you have successfully authenticated. To authenticate, call one of the AuthenticateAsClient, AuthenticateAsClientAsync, BeginAuthenticateAsClient, AuthenticateAsServer, AuthenticateAsServerAsync, or BeginAuthenticateAsServer methods.