UdpSingleSourceMulticastClient.BeginJoinGroup Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Binds the socket and begins a join operation to the multicast group to allow datagrams to be received from a single source address.
Assembly: System.Net (in System.Net.dll)
'Declaration Public Function BeginJoinGroup ( _ callback As AsyncCallback, _ state As Object _ ) As IAsyncResult
Parameters
- callback
- Type: System.AsyncCallback
A callback method to invoke when the operation completes.
- state
- Type: System.Object
Optional state information to pass to the callback method for this operation.
| Exception | Condition |
|---|---|
| InvalidOperationException | The multicast group has already been joined or a join operation is currently in progress. |
| ObjectDisposedException | The UdpSingleSourceMulticastClient has been disposed. |
| SocketException | An error occurred when attempting to access the socket. See the Remarks section for more information. |
The BeginJoinGroup method binds a UDP multicast socket to a local port and joins a multicast group to allow datagrams to be received from a single source address. The multicast group address, single source address, and local port to bind to are specified in the UdpSingleSourceMulticastClient constructor.
The method specified in the callback parameter is invoked when the operation to join the multicast group has completed.
If required by the runtime, the BeginJoinGroup method also performs a policy check to verify that the client is allowed to access the multicast group. If the client is not allowed access, a SocketException is thrown with SocketError.AccessDenied.