Socket.EndSendTo(IAsyncResult) Method

Reference

Definition

Namespace:: System.Net.Sockets

Assembly:: System.Net.Sockets.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Source:: Socket.cs

Source:: Socket.cs

Source:: Socket.cs

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 send to a specific location.

public:
 int EndSendTo(IAsyncResult ^ asyncResult);

public int EndSendTo (IAsyncResult asyncResult);

member this.EndSendTo : IAsyncResult -> int

Public Function EndSendTo (asyncResult As IAsyncResult) As Integer

Parameters

asyncResult: IAsyncResult

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

Returns

Int32

If successful, the number of bytes sent; otherwise, an invalid Socket error.

Exceptions

ArgumentNullException

asyncResult is null.

ArgumentException

asyncResult was not returned by a call to the BeginSendTo(Byte[], Int32, Int32, SocketFlags, EndPoint, AsyncCallback, Object) method.

InvalidOperationException

EndSendTo(IAsyncResult) was previously called for the asynchronous send.

SocketException

An error occurred when attempting to access the socket.

-or-

.NET 7+ only: The Socket has been closed.

ObjectDisposedException

.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.

EndSendTo completes the operation started by BeginSendTo. You need to pass the IAsyncResult created by the matching BeginSendTo call.

If you are using a connectionless protocol, EndSendTo will block until the datagram is sent. If you are using a connection-oriented protocol, EndSendTo will block until the requested number of bytes are sent. There is no guarantee that the data you send will appear on the network immediately. To increase network efficiency, the underlying system may delay transmission until a significant amount of outgoing data is collected. A successful completion of the BeginSendTo method means that the underlying system has had room to buffer your data for a network send.

Note

If you receive a SocketException, use the SocketException.ErrorCode property to obtain the specific error code. After you have obtained this code, refer to the Windows Sockets version 2 API error code documentation for a detailed description of the error.