Option Explicit On
Option Strict On
Public Class myProg
    Inherits Form
    '// Designer
 
    Private myTimer As System.Windows.Forms.Timer
    Private down As Integer
 
    Private Sub myTimer_Tick(ByVal sender As System.Object, ByVal e As _
      EventArgs)
        If (Environment.TickCount - down) > 600 Then
            myTimer.Enabled = False
            Me.zeichneNeu()
        End If
    End Sub
 
    Private Sub myProg_Load(ByVal sender As Object, ByVal e As EventArgs) _
      Handles MyBase.Load
        Me.KeyPreview = True
        myTimer = New System.Windows.Forms.Timer
        myTimer.Interval = 100
        AddHandler myTimer.Tick, AddressOf myTimer_Tick
    End Sub
 
    Private Sub myProg_KeyUp(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.KeyEventArgs) Handles Me.KeyUp
        If ((e.Modifiers = Keys.Control) AndAlso _ 
            (e.KeyCode = Keys.Oemplus OrElse e.KeyCode = Keys.Add)) Then
            Me.zoomIn()
            Me.myTimer.Enabled = True
        ElseIf ((e.Modifiers = Keys.Control) AndAlso _
            (e.KeyCode = Keys.OemMinus OrElse e.KeyCode = Keys.Subtract)) Then
            Me.zoomOut()
            Me.myTimer.Enabled = True
        End If
    End Sub
 
    Private Sub myProg_KeyDown(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
        If ((e.Modifiers = Keys.Control) AndAlso _
            (e.KeyCode = Keys.Oemplus OrElse e.KeyCode = Keys.Add)) Then
            down = Environment.TickCount
        ElseIf ((e.Modifiers = Keys.Control) AndAlso _
            (e.KeyCode = Keys.OemMinus OrElse e.KeyCode = Keys.Subtract)) Then
            down = Environment.TickCount
        End If
    End Sub
 
    Private Sub zeichneNeu()
        '// zeichne neu
        MessageBox.Show("Zeichne neu")
 
    End Sub
 
    Private Sub zoomIn()
        '// zoom in
 
    End Sub
 
    Private Sub zoomOut()
        '// zoom out
 
    End Sub
End Class