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TransformChanged Event
See Also 
Leadtools.Windows.Controls Namespace > ImageViewer Class : TransformChanged Event



Occurs when any visual transformation properties changes in the control. Supported in Silverlight, Windows Phone 7

Syntax

Visual Basic (Declaration) 
Public Event TransformChanged As EventHandler
Visual Basic (Usage)Copy Code
Dim instance As ImageViewer
Dim handler As EventHandler
 
AddHandler instance.TransformChanged, handler
C# 
public event EventHandler TransformChanged
C++/CLI 
public:
event EventHandler^ TransformChanged

Example

Visual BasicCopy Code
Private Sub viewer_TransformChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim viewer As ImageViewer = TryCast(sender, ImageViewer)
    Dim s As String = String.Format("TransformChanged Event: {0}", viewer.Transform.ToString())
    MessageBox.Show(s)
End Sub
Public Sub ImageViewer_TransformChanged(ByVal viewer As ImageViewer)
    AddHandler viewer.TransformChanged, AddressOf viewer_TransformChanged

    Select Case viewer.SizeMode
        Case SizeMode.Fit
            viewer.SizeMode = SizeMode.FitAlways

        Case SizeMode.FitAlways
            viewer.SizeMode = SizeMode.FitWidth

        Case SizeMode.FitWidth
            viewer.SizeMode = SizeMode.Normal

        Case SizeMode.Normal
            viewer.SizeMode = SizeMode.Stretch

        Case SizeMode.Stretch
            viewer.SizeMode = SizeMode.Fit
    End Select

    RemoveHandler viewer.TransformChanged, AddressOf viewer_TransformChanged
End Sub
C#Copy Code
private void viewer_TransformChanged(object sender, EventArgs e)
{
   ImageViewer viewer = sender as ImageViewer;
   string s = string.Format("TransformChanged Event: {0}", viewer.Transform.ToString());
   MessageBox.Show(s);
}
public void ImageViewer_TransformChanged(ImageViewer viewer)
{
   viewer.TransformChanged += new EventHandler(viewer_TransformChanged);

   switch (viewer.SizeMode)
   {
      case SizeMode.Fit:
         viewer.SizeMode = SizeMode.FitAlways;
         break;

      case SizeMode.FitAlways:
         viewer.SizeMode = SizeMode.FitWidth;
         break;

      case SizeMode.FitWidth:
         viewer.SizeMode = SizeMode.Normal;
         break;

      case SizeMode.Normal:
         viewer.SizeMode = SizeMode.Stretch;
         break;

      case SizeMode.Stretch:
         viewer.SizeMode = SizeMode.Fit;
         break;
   }

   viewer.TransformChanged -= new EventHandler(viewer_TransformChanged);
}
SilverlightCSharpCopy Code
private void viewer_TransformChanged(object sender, EventArgs e)
{
   ImageViewer viewer = sender as ImageViewer;
   string s = string.Format("TransformChanged Event: {0}", viewer.Transform.ToString());
   MessageBox.Show(s);
}
public void ImageViewer_TransformChanged(ImageViewer viewer)
{
   viewer.TransformChanged += new EventHandler(viewer_TransformChanged);

   switch (viewer.SizeMode)
   {
      case SizeMode.Fit:
         viewer.SizeMode = SizeMode.FitAlways;
         break;

      case SizeMode.FitAlways:
         viewer.SizeMode = SizeMode.FitWidth;
         break;

      case SizeMode.FitWidth:
         viewer.SizeMode = SizeMode.Normal;
         break;

      case SizeMode.Normal:
         viewer.SizeMode = SizeMode.Stretch;
         break;

      case SizeMode.Stretch:
         viewer.SizeMode = SizeMode.Fit;
         break;
   }

   viewer.TransformChanged -= new EventHandler(viewer_TransformChanged);
}
SilverlightVBCopy Code
Private Sub viewer_TransformChanged(ByVal sender As Object, ByVal e As EventArgs)
   Dim viewer As ImageViewer = TryCast(sender, ImageViewer)
   Dim s As String = String.Format("TransformChanged Event: {0}", viewer.Transform.ToString())
   MessageBox.Show(s)
End Sub
Public Sub ImageViewer_TransformChanged(ByVal viewer As ImageViewer)
   AddHandler viewer.TransformChanged, AddressOf viewer_TransformChanged

   Select Case viewer.SizeMode
      Case SizeMode.Fit
         viewer.SizeMode = SizeMode.FitAlways

      Case SizeMode.FitAlways
         viewer.SizeMode = SizeMode.FitWidth

      Case SizeMode.FitWidth
         viewer.SizeMode = SizeMode.Normal

      Case SizeMode.Normal
         viewer.SizeMode = SizeMode.Stretch

      Case SizeMode.Stretch
         viewer.SizeMode = SizeMode.Fit
   End Select

   RemoveHandler viewer.TransformChanged, AddressOf viewer_TransformChanged
End Sub

Remarks

This event is raised if any of the properties of the controls that effects the way the image will be displayed is changed such as:

You can use the TransformChanged event as catch all placeholder to update external properties or UI elements whenever the user scrolls or zooms the image for example instead of hooking to individual properties OnXYZChanged events.

Requirements

Target Platforms: Windows 2000, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also

Reference

ImageViewer Class
ImageViewer Members