Socket.EndSend Method

Definition

Namespace:

System.Net.Sockets

Assembly:

System.Net.Sockets.dll

Ends a pending asynchronous send.

Overloads

EndSend(IAsyncResult)	Ends a pending asynchronous send.
EndSend(IAsyncResult, SocketError)	Ends a pending asynchronous send.

EndSend(IAsyncResult)

Source:

Socket.cs

Ends a pending asynchronous send.

public:
 int EndSend(IAsyncResult ^ asyncResult);

public int EndSend (IAsyncResult asyncResult);

member this.EndSend : IAsyncResult -> int

Public Function EndSend (asyncResult As IAsyncResult) As Integer

Parameters

asyncResult

IAsyncResult

An IAsyncResult that stores state information for this asynchronous operation.

Returns

Int32

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

Exceptions

ArgumentNullException

asyncResult is null.

ArgumentException

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

InvalidOperationException

EndSend(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.

EndSend completes the operation started by BeginSend. You need to pass the IAsyncResult created by the matching BeginSend call.

If you are using a connectionless protocol, EndSend will block until the datagram is sent. If you are using a connection-oriented protocol, EndSend will block until some of the buffer was sent. If the return value from EndSend indicates that the buffer was not completely sent, call the BeginSend method again, modifying the buffer to hold the unsent data.

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 BeginSend 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.

Note

All I/O initiated by a given thread is canceled when that thread exits. A pending asynchronous operation can fail if the thread exits before the operation completes.

Note

The successful completion of a send does not indicate that the data was successfully delivered. If no buffer space is available within the transport system to hold the data to be transmitted, send will block unless the socket has been placed in nonblocking mode.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

See also

• BeginSend(Byte[], Int32, Int32, SocketFlags, AsyncCallback, Object)
• AsyncCallback
• AsyncState
• SetSocketOption(SocketOptionLevel, SocketOptionName, Int32)
• NoDelay

EndSend(IAsyncResult, SocketError)

Source:

Socket.cs

Ends a pending asynchronous send.

public:
 int EndSend(IAsyncResult ^ asyncResult, [Runtime::InteropServices::Out] System::Net::Sockets::SocketError % errorCode);

public int EndSend (IAsyncResult asyncResult, out System.Net.Sockets.SocketError errorCode);

member this.EndSend : IAsyncResult * SocketError -> int

Public Function EndSend (asyncResult As IAsyncResult, ByRef errorCode As SocketError) As Integer

Parameters

asyncResult

IAsyncResult

An IAsyncResult that stores state information for this asynchronous operation.

errorCode

SocketError

A SocketError object that stores the socket error.

Returns

Int32

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

Exceptions

ArgumentNullException

asyncResult is null.

ArgumentException

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

InvalidOperationException

EndSend(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.

EndSend completes the operation started by BeginSend. You need to pass the IAsyncResult created by the matching BeginSend call.

If you are using a connectionless protocol, EndSend will block until the datagram is sent. If you are using a connection-oriented protocol, EndSend will block until some of the buffer was sent. If the return value from EndSend indicates that the buffer was not completely sent, call the BeginSend method again, modifying the buffer to hold the unsent data.

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 BeginSend 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.

Note

All I/O initiated by a given thread is canceled when that thread exits. A pending asynchronous operation can fail if the thread exits before the operation completes.

Note

The successful completion of a send does not indicate that the data was successfully delivered. If no buffer space is available within the transport system to hold the data to be transmitted, send will block unless the socket has been placed in nonblocking mode.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

See also

• BeginSend(Byte[], Int32, Int32, SocketFlags, AsyncCallback, Object)
• AsyncCallback
• AsyncState
• SetSocketOption(SocketOptionLevel, SocketOptionName, Int32)
• NoDelay