Zooming In on a Selection (Visual Basic)

Take the following steps to add code that lets you select an area with a mouse, and zoom in on the selected area.

1.	Start with the project that you created in Loading and Displaying an Image.
2.	In the LEADRasterView1 control's MouseDown procedure, add the following code. In online help, you can use the Edit pull-down menu to copy the block of code.

Private Sub LEADRasterView1_MouseDown(ByVal Button As Integer, ByVal Shift As Integer, ByVal x As Single, ByVal y As Single)
   'Enable AutoRubberBand
   LEADRasterView1.AutoRubberBand = True
   LEADRasterView1.MousePointer = 2
End Sub

3.	In the LEADRasterView1 control's Rubberband procedure, add the following code.

Private Sub LEADRasterView1_RubberBand ()
  Dim zoomleft As Integer
  Dim zoomtop As Integer
  Dim zoomwidth As Integer
  Dim zoomheight As Integer
   LEADRasterView1.MousePointer = 0
   'Zoom in on the selection.
   zoomleft = LEADRasterView1.RubberBandLeft
   zoomtop = LEADRasterView1.RubberBandTop
   zoomwidth = LEADRasterView1.RubberBandWidth
   zoomheight = LEADRasterView1.RubberBandHeight
   'Zoom in on the rectangle defined by the rubberband
   LEADRasterView1.ZoomToRect zoomleft, zoomtop, zoomwidth, zoomheight
   LEADRasterView1.ForceRepaint
End Sub

4.	Run your program to test it.