Public Class Form1
 
    Private Abbruch As Boolean
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        'Abbruch Button
        Abbruch = True
    End Sub
 
    Private Sub SendkeyRoutine()
        Do
            For Each s As String In ListBox1.Items
                'hier Sendkeys.......
                System.Threading.Thread.Sleep(500) ' 1/2 sekunde warten
                Application.DoEvents()
                If Abbruch Then Exit Do
            Next
 
            For t As Integer = 1 To 50
                System.Threading.Thread.Sleep(100) '50 * 0.1 sek warten
                Application.DoEvents()
                If Abbruch Then Exit Do
            Next
        Loop
    End Sub
 
End Class

Gru?

Silver