CenterZoomAtPointScaleFactor Property

C#
Visual Basic
Objective-C
Java
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;}

'Declaration
 
<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

'Usage
 
Dim instance As RasterImageViewer
Dim value As Double
 
instance.CenterZoomAtPointScaleFactor = value
 
value = instance.CenterZoomAtPointScaleFactor

[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 value);
}

Property Value

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

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

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.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

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;
      }
   }
}

Target Platforms

Reference

RasterImageViewer Class
RasterImageViewer Members