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CenterZoomAtPointScaleFactor Property

Summary

Gets or sets the scale factor used to zoom the image in the viewer around the center when CenterAtPoint is called.

Syntax

C++

[DefaultValueAttribute()] 
[DescriptionAttribute("The zoom factor used when calling CenterAtPoint or when the interactive mode was set to ZoomAt. A value of 1 = no scale. A value greater than 1 will zoom the image around the center point by that amount. A value less than 1 will zoom the image around the center point by that amount.")] 
[CategoryAttribute("Behavior")] 
public virtual double CenterZoomAtPointScaleFactor {get; set;}

<DefaultValueAttribute()> 
<DescriptionAttribute("The zoom factor used when calling CenterAtPoint or when the interactive mode was set to ZoomAt. A value of 1 = no scale. A value greater than 1 will zoom the image around the center point by that amount. A value less than 1 will zoom the image around the center point by that amount.")> 
<CategoryAttribute("Behavior")> 
Public Overridable Property CenterZoomAtPointScaleFactor As Double

[DefaultValueAttribute()] 
[DescriptionAttribute("The zoom factor used when calling CenterAtPoint or when the interactive mode was set to ZoomAt. A value of 1 = no scale. A value greater than 1 will zoom the image around the center point by that amount. A value less than 1 will zoom the image around the center point by that amount.")] 
[CategoryAttribute("Behavior")] 
public: 
virtual property double CenterZoomAtPointScaleFactor { 
   double get(); 
   void set (    double ); 
}

Property Value

The scale factor used to display the magnified image. Must be a value greater than 0. Default value is 1 (no zoom).

Remarks

Use the value of CenterZoomAtPointScaleFactor to perform zooming of the image around the center point when calling CenterAtPoint:

If the value of CenterZoomAtPointScaleFactor is 1 (the default value), then no zooming is performed
If the value of CenterZoomAtPointScaleFactor is greater than 1, then this value is multiplied by the current viewer scale factor (ScaleFactor) to zoom the image in around the center point
If the value of ScaleFactor is less than 1, then this value is multiplied by the current viewer scale factor (ScaleFactor) to zoom the image out around the center point

Example

This example will set the viewer interactive mode to "center", it will also alternate the scale factor used with each click between 2 and 0.5. When you run this example, the first click on the viewer will center the image around that point while zooming it in twice. When you click again, the viewer will center the image around that point while zommong it out twice. Subsequent clicks will repeat these operations.

Imports Leadtools.WinForms 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Drawing 
 
Private Shared Sub CenterAtWithZoomExample(ByVal viewer As RasterImageViewer) 
   ' Make sure the viewer size mode is normal 
   viewer.SizeMode = RasterPaintSizeMode.Normal 
   ' Set interactive mode to CenterAt 
   viewer.InteractiveMode = RasterViewerInteractiveMode.CenterAt 
 
   ' Set the center at scale factor to 1, so zoom in twice with each click 
   viewer.CenterZoomAtPointScaleFactor = 2.0 
 
   AddHandler viewer.InteractiveModeEnded, AddressOf rasterImageviewer_InteractiveModeEnded 
End Sub 
 
Private Shared Sub rasterImageviewer_InteractiveModeEnded(ByVal sender As Object, ByVal e As EventArgs) 
   ' Check if this is the Center At interactive mode 
   Dim viewer As RasterImageViewer = CType(sender, RasterImageViewer) 
   If viewer.InteractiveMode = RasterViewerInteractiveMode.CenterAt Then 
      If viewer.CenterZoomAtPointScaleFactor = 2.0 Then 
         ' Switch the scale factor to 0.5, so next time we click, it will zoom out twice 
         viewer.CenterZoomAtPointScaleFactor = 0.5 
      Else 
         ' Back to 2, so we zoom in 
         viewer.CenterZoomAtPointScaleFactor = 2.0 
      End If 
   End If 
End Sub

using Leadtools.WinForms; 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Drawing; 
 
private static void CenterAtWithZoomExample(RasterImageViewer viewer) 
{ 
   // Make sure the viewer size mode is normal 
   viewer.SizeMode = RasterPaintSizeMode.Normal; 
   // Set interactive mode to CenterAt 
   viewer.InteractiveMode = RasterViewerInteractiveMode.CenterAt; 
 
   // Set the center at scale factor to 1, so zoom in twice with each click 
   viewer.CenterZoomAtPointScaleFactor = 2.0; 
 
   viewer.InteractiveModeEnded += viewer_InteractiveModeEnded; 
} 
private static void viewer_InteractiveModeEnded(object sender, EventArgs e) 
{ 
   // Check if this is the Center At interactive mode 
   RasterImageViewer viewer = sender as RasterImageViewer; 
   if (viewer.InteractiveMode == RasterViewerInteractiveMode.CenterAt) 
   { 
      if (viewer.CenterZoomAtPointScaleFactor == 2.0) 
      { 
         // Switch the scale factor to 0.5, so next time we click, it will zoom out twice 
         viewer.CenterZoomAtPointScaleFactor = 0.5; 
      } 
      else 
      { 
         // Back to 2, so we zoom in 
         viewer.CenterZoomAtPointScaleFactor = 2.0; 
      } 
   } 
}