Socket.EndReceiveFrom(IAsyncResult, EndPoint) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Ends a pending asynchronous read from a specific endpoint.
public:
int EndReceiveFrom(IAsyncResult ^ asyncResult, System::Net::EndPoint ^ % endPoint);public int EndReceiveFrom (IAsyncResult asyncResult, ref System.Net.EndPoint endPoint);member this.EndReceiveFrom : IAsyncResult * EndPoint -> intPublic Function EndReceiveFrom (asyncResult As IAsyncResult, ByRef endPoint As EndPoint) As IntegerParameters
- asyncResult
- IAsyncResult
An IAsyncResult that stores state information and any user defined data for this asynchronous operation.
Returns
If successful, the number of bytes received. If unsuccessful, returns 0.
Exceptions
asyncResult is null.
asyncResult was not returned by a call to the BeginReceiveFrom(Byte[], Int32, Int32, SocketFlags, EndPoint, AsyncCallback, Object) method.
EndReceiveFrom(IAsyncResult, EndPoint) was previously called for the asynchronous read.
An error occurred when attempting to access the socket.
-or-
.NET 7+ only: The Socket has been closed.
.NET Framework, .NET Core, and .NET 5-6 only: The Socket has been closed.
Remarks
Important
This is a compatibility API. We don't recommend using the APM (Begin* and End*) methods for new development. Instead, use the Task-based equivalents.
EndReceiveFrom completes the operation started by BeginReceiveFrom. You need to pass the IAsyncResult created by the matching BeginReceiveFrom call.
The EndReceiveFrom method will block until data is available. If you are using a connectionless protocol, EndReceiveFrom will read the first enqueued datagram available in the incoming network buffer. If you are using a connection-oriented protocol, the EndReceiveFrom method will read as much data as is available up to the number of bytes you specified in the size parameter of the BeginReceiveFrom method. If the remote host shuts down the Socket connection with the Shutdown method, and all available data has been received, the EndReceiveFrom method will complete immediately and return zero bytes. To obtain the received data, call the AsyncState method of the IAsyncResult object, and extract the buffer contained in the resulting state object. To identify the originating host, extract the EndPoint and cast it to an IPEndPoint. Use the IPEndPoint.Address method to obtain the IP address and the IPEndPoint.Port method to obtain the port number.
Note
If you receive a SocketException, use the SocketException.ErrorCode property to obtain the specific error code.
Note
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.
