UDP connection doesn't fire _sendcomplete?

[opus]

Hi,I'm using the following code for an array of TCP connections.
It prevents errors from a blocked connection if a second message has to be sent through that WinsockTCP array. That works so far.
But I tried to use the exact same with a UDP connection, the problem seams to be that the WinSockUPD_SendComplete(Index As Integer) Sub never fires. Why is that?

Dim SendCompleteTCP as Boolean
Dim Message as String
 
Public Sub WinsockTCP_senden(Verbindung As Integer, Message As String)
SendCompleteTCP = False
WinSockTCP(Verbindung).SendData Message
Do
    DoEvents
Loop Until SendCompleteTCP = True
End Sub
 
Private Sub WinSockTCP_SendComplete(Index As Integer)
SendCompleteTCP = True
End Sub