Socket.BeginReceiveMessageFrom(Byte[], Int32, Int32, SocketFlags, EndPoint, AsyncCallback, Object) Method


Begins to asynchronously receive the specified number of bytes of data into the specified location of the data buffer, using the specified SocketFlags, and stores the endpoint and packet information.

 IAsyncResult ^ BeginReceiveMessageFrom(cli::array <System::Byte> ^ buffer, int offset, int size, System::Net::Sockets::SocketFlags socketFlags, System::Net::EndPoint ^ % remoteEP, AsyncCallback ^ callback, System::Object ^ state);
public IAsyncResult BeginReceiveMessageFrom (byte[] buffer, int offset, int size, System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, AsyncCallback? callback, object? state);
public IAsyncResult BeginReceiveMessageFrom (byte[] buffer, int offset, int size, System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, AsyncCallback callback, object state);
member this.BeginReceiveMessageFrom : byte[] * int * int * System.Net.Sockets.SocketFlags * EndPoint * AsyncCallback * obj -> IAsyncResult
Public Function BeginReceiveMessageFrom (buffer As Byte(), offset As Integer, size As Integer, socketFlags As SocketFlags, ByRef remoteEP As EndPoint, callback As AsyncCallback, state As Object) As IAsyncResult



An array of type Byte that is the storage location for the received data.


The zero-based position in the buffer parameter at which to store the data.


The number of bytes to receive.


A bitwise combination of the SocketFlags values.


An EndPoint that represents the source of the data.


The AsyncCallback delegate.


An object that contains state information for this request.



An IAsyncResult that references the asynchronous read.


buffer is null.


remoteEP is null.

An error occurred when attempting to access the socket.

offset is less than 0.


offset is greater than the length of buffer.


size is less than 0.


size is greater than the length of buffer minus the value of the offset parameter.

The Socket has been closed.


The asynchronous receive operation must be completed by calling the EndReceiveMessageFrom method. Typically, the method is invoked by the asyncCallback delegate.

This method does not block until the operation completes. To block until the operation completes, use the ReceiveMessageFrom method.

To cancel a pending BeginReceiveMessageFrom, call the Close method.

For detailed information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously

This method reads data into the buffer parameter, and captures the remote host endpoint from which the data is sent, as well as information about the received packet. For information on how to retrieve this endpoint, refer to EndReceiveFrom. This method is most useful if you intend to asynchronously receive connectionless datagrams from an unknown host or multiple hosts.


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.


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


The execution context (the security context, the impersonated user, and the calling context) is cached for the asynchronous Socket methods. After the first use of a particular context (a specific asynchronous Socket method, a specific Socket instance, and a specific callback), subsequent uses of that context will see a performance improvement.

Applies to