Public Class frmKillProcess
 
    Dim WithEvents btnStart As New Button With _
         {.Parent = Me, .Text = "Start Text"}
 
    Dim WithEvents btnEnd As New Button With _
         {.Parent = Me, .Text = "End Text", .Left = 200}
 
 
    Dim p As Process
 
 
    Public Sub StartText()
        p = Process.Start("C:\Daten\gewichte.txt")
        p.WaitForExit()
 
        'Code, der nach Beendigung des Prozesses auszuführen ist
    End Sub
 
 
    Private Sub btnStart_Click(sender As Object, _
        e As System.EventArgs) Handles btnStart.Click
 
        Dim t As New System.Threading.Thread(AddressOf StartText)
        t.Start()
    End Sub
 
 
    Private Sub btnEnd_Click(sender As Object, _
        e As System.EventArgs) Handles btnEnd.Click
 
        If p IsNot Nothing Then
            If Not p.HasExited Then
                p.Kill()
                p.Close()
                p = Nothing
            End If
        End If
    End Sub
 
End Class

p.WaitForExit()

Public Class frmKillProcess
 
    Dim WithEvents btnStart As New Button _
        With {.Parent = Me, .Text = "Start Text"}
 
    Dim WithEvents btnEnd As New Button With _
       {.Parent = Me, .Text = "End Text", .Left = 200, .Enabled = False}
 
 
    Dim p As Process
 
    Dim Canceled As Boolean
    Dim Running As Boolean
 
 
    Private Sub Finished()
        'Threadende bearbeiten
        btnEnd.Text = "beendet"
        Running = False
    End Sub
 
 
    Public Sub StartText()
 
        Do
            'Prozesse nacheinander starten
            p = Process.Start("C:\Daten\gewichte.txt")
            p.WaitForExit()
        Loop While Not Canceled
 
        'Methode für Threadende-Bearbeitung invoken
        Me.Invoke(New MethodInvoker(AddressOf Finished))
    End Sub
 
 
    Private Sub btnStart_Click(sender As Object, _
        e As System.EventArgs) Handles btnStart.Click
 
        If Running Then Exit Sub
 
        Dim t As New System.Threading.Thread(AddressOf StartText)
 
        Canceled = False
        Running = True
        btnEnd.Text = "End Text"
        btnEnd.Enabled = true
        t.Start()
    End Sub
 
 
    Private Sub btnEnd_Click(sender As Object, _
        e As System.EventArgs) Handles btnEnd.Click
 
        If p IsNot Nothing Then
            If Not p.HasExited Then
                'Notieren, 
                'dass kein neuer Thread gestartet werden soll
                btnEnd.Text = "Bitte warten"
                btnEnd.enabled = false 
                Canceled = True
            End If
          End If
    End Sub
 
End Class