VB.NET

Poll a Socket for Available Data

Demonstrates Socket.PollDataAvailable, which performs a nonblocking check for readable activity and returns whether data or another read-ready condition is present.

Background. This lets an application check for incoming data without blocking, for example in an event loop that services multiple tasks.

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VB.NET

Dim success As Boolean = False

Dim socket As New Chilkat.Socket

'  Connect to the server using TLS.
Dim bTls As Boolean = True
Dim maxWaitMs As Integer = 5000
success = socket.Connect("example.com",5000,bTls,maxWaitMs)
If (success = False) Then
    Debug.WriteLine(socket.LastErrorText)
    Exit Sub
End If


'  Perform a nonblocking check for readable data.  Returns True when data or another read-ready
'  condition is present, and False when nothing is immediately available.
Dim bAvailable As Boolean = socket.PollDataAvailable()
If (bAvailable <> True) Then
    Debug.WriteLine("No data is immediately available.")
Else
    Debug.WriteLine("Data is available to read.")
End If