Imports System.Windows.Forms
Imports System.Drawing
Imports System.Drawing.Drawing2D
 
Public Class Form1
    Dim x As Integer = 0
    Dim y As Integer = 0
    Dim z As Integer = 40
    Dim x_alt, y_alt As Integer
    Dim g As Graphics = CreateGraphics()
    Dim run As Boolean
 
    Sub zeichen()
        g.FillRectangle(Brushes.Black, x_alt, y_alt, z, z)
        g.FillRectangle(Brushes.Green, x, y, z, z)
    End Sub
    Sub back()
        g.DrawLine(Pens.White, 0, 0, Me.ClientSize.Width, Me.ClientSize.Height)
        g.DrawLine(Pens.White, 0, Me.ClientSize.Height, Me.ClientSize.Width, 0)
    End Sub
 
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles Me.Load
        g.FillRectangle(Brushes.Black, 0, 0, Me.Width, Me.Height)
        back()
        zeichen()
    End Sub
 
    Private Sub Form1_MouseClick(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles Me.MouseClick
        If run Then
            run = False
        End If
    End Sub
 
    Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        If e.X > x And e.X < x + z Then
            If e.Y > y And e.Y < y + z Then
                g.FillRectangle(Brushes.Black, x, y, z, z)
                run = True
                Form1_MouseMove(sender, e)
            End If
        End If
    End Sub
 
    Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
        If run = True Then
            x_alt = x
            y_alt = y
            x = e.X - 20
            y = e.Y
            If e.X < Me.Width And e.Y < Me.Height Then
                back()
                zeichen()
            End If
        End If
    End Sub
 
    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        g.FillRectangle(Brushes.Black, 0, 0, Me.Width, Me.Height)
        back()
        zeichen()
    End Sub
 
End Class