Private Type POINTAPI
    X As Long
    Y As Long
End Type
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Dim oldmp As POINTAPI
Dim ydiff As Integer
Dim xdiff As Integer
 
Private Sub Form_Load()
  ydiff = (Form1.Height - Form1.ScaleHeight)
  xdiff = (Form1.Width - Form1.ScaleWidth)
  Picture1.Visible = False
  Picture1.Left = Screen.TwipsPerPixelX * 2 - xdiff
  Picture1.Top = Screen.TwipsPerPixelY * 2 - ydiff
  Picture1.ScaleMode = vbPixels
  ydiff = Form1.Top / Screen.TwipsPerPixelY
  xdiff = Form1.Left / Screen.TwipsPerPixelX
  Dim mp As POINTAPI
  GetCursorPos mp
  oldmp.X = mp.X - xdiff
  oldmp.Y = mp.Y - ydiff
  Timer1.Enabled = True
End Sub
 
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  SavePicture Picture1.Image, "c:windowsdesktoplines.bmp"
End Sub
 
Private Sub Form_Resize()
  Picture1.Width = Form1.Width
  Picture1.Height = Form1.Height
End Sub
 
Private Sub Timer1_Timer()
  ydiff = Form1.Top / Screen.TwipsPerPixelY
  xdiff = Form1.Left / Screen.TwipsPerPixelX
  Dim mp As POINTAPI
  GetCursorPos mp
  mp.X = mp.X - xdiff
  mp.Y = mp.Y - ydiff
  Picture1.Line (oldmp.X, oldmp.Y)-(mp.X, mp.Y)
  oldmp.X = mp.X
  oldmp.Y = mp.Y
End Sub