Socket.EndReceiveFrom(IAsyncResult, EndPoint) Method

Definition

Ends a pending asynchronous read from a specific endpoint.

public int EndReceiveFrom (IAsyncResult asyncResult, ref System.Net.EndPoint endPoint);

Parameters

asyncResult
IAsyncResult

An IAsyncResult that stores state information and any user defined data for this asynchronous operation.

endPoint
EndPoint

The source EndPoint.

Returns

If successful, the number of bytes received. If unsuccessful, returns 0.

Exceptions

asyncResult is null.

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.

Applies to

Product Versions
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1