Poll Method

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Determines the status of the Socket.

Namespace:  System.Net.Sockets
Assembly:  System (in System.dll)

'Declaration
Public Function Poll ( _
	microSeconds As Integer, _
	mode As SelectMode _
) As Boolean

Parameters

microSeconds
Type: System..::..Int32
The time to wait for a response, in microseconds.
mode
Type: System.Net.Sockets..::..SelectMode
One of the SelectMode values.

Return Value

Type: System..::..Boolean
The status of the Socket based on the polling mode value passed in the mode parameter.

Mode

Return Value

SelectRead

true if Listen has been called and a connection is pending;

-or-

true if data is available for reading;

-or-

true if the connection has been closed, reset, or terminated;

otherwise, returns false.

SelectWrite

true, if processing a Connect, and the connection has succeeded;

-or-

true if data can be sent;

otherwise, returns false.

SelectError

true if processing a Connect that does not block, and the connection has failed;

-or-

true if OutOfBandInline is not set and out-of-band data is available;

otherwise, returns false.

The Poll method will check the state of the Socket. Specify SelectMode..::..SelectRead for the selectMode parameter to determine if the Socket is readable. Specify SelectMode..::..SelectWrite to determine if the Socket is writable. Use SelectMode..::..SelectError to detect an error condition. Poll will block execution until the specified time period, measured in microseconds, elapses. Set the microSeconds parameter to a negative integer if you would like to wait indefinitely for a response. If you want to check the status of multiple sockets, you might prefer to use the Select method.

NoteNote

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 in the MSDN library for a detailed description of the error.

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