TcpClient::BeginConnect Method (String^, Int32, AsyncCallback^, Object^)
Begins an asynchronous request for a remote host connection. The remote host is specified by a host name (String) and a port number (Int32).
Assembly: System (in System.dll)
public: [HostProtectionAttribute(SecurityAction::LinkDemand, ExternalThreading = true)] IAsyncResult^ BeginConnect( String^ host, int port, AsyncCallback^ requestCallback, Object^ state )
Parameters
- host
-
Type:
System::String^
The name of the remote host.
- port
-
Type:
System::Int32
The port number of the remote host.
- requestCallback
-
Type:
System::AsyncCallback^
An AsyncCallback delegate that references the method to invoke when the operation is complete.
- state
-
Type:
System::Object^
A user-defined object that contains information about the connect operation. This object is passed to the requestCallback delegate when the operation is complete.
Return Value
Type: System::IAsyncResult^An IAsyncResult object that references the asynchronous connection.
| Exception | Condition |
|---|---|
| ArgumentNullException | The host parameter is null. |
| SocketException | An error occurred when attempting to access the socket. See the Remarks section for more information. |
| ObjectDisposedException | The Socket has been closed. |
| SecurityException | A caller higher in the call stack does not have permission for the requested operation. |
| ArgumentOutOfRangeException | The port number is not valid. |
The asynchronous BeginConnect operation must be completed by calling the EndConnect method. Typically, the method is invoked by the asyncCallback delegate.
This method does not block until the operation completes. To block until the operation completes, use one of the Connect method overloads.
For detailed information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously.
The following code example creates a TcpClient and connects to a remote host.
// Connect asynchronously to the specifed host. static void DoBeginConnect3( String^ host, int port ) { TcpClient^ t = gcnew TcpClient( AddressFamily::InterNetwork ); connectDone->Reset(); Console::WriteLine( "Establishing Connection to {0}", host ); t->BeginConnect( host, port, gcnew AsyncCallback( &ConnectCallback ), t ); // Wait here until the callback processes the connection. connectDone->WaitOne(); Console::WriteLine( "Connection established" ); }
Available since 2.0