PropertyChanged Event (ImageViewer)

The event handler receives an argument of type PropertyChangedEventArgs containing data related to this event. The following PropertyChangedEventArgs properties provide information specific to this event.

Most of the properties of this ImageViewer will fire the PropertyChanged event when the value changes. When this happens, the value of PropertyChangedEventArgs.PropertyName of the event data will be set to the name of the property that was changed. For example, the PropertyChangedEventArgs.PropertyName will be set to "UseDpi" when UseDpi changes and "ScrollOffset" when ScrollOffset changes.

Run the demo and now as you click the Example button, the label is updated.

Start with the ImageViewer example, remove all the code inside the example function (search for the "// TODO: add example code here" comment) and insert the following code:

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

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Imports Leadtools
Imports Leadtools.Controls
Imports Leadtools.Codecs
Imports Leadtools.Drawing
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Color

If _firstCall Then
   _firstCall = False
   ' Subscribe to PropertyChanged event
   AddHandler _imageViewer.PropertyChanged,
      Sub(sender, e)
         If e.PropertyName = "Flip" Then
            If _imageViewer.Flip Then
               _label.Text = "Image is flipped"
            Else
               _label.Text = "Image is not flipped"
            End If
         End If
      End Sub
End If
' Change the flip state of the image
_imageViewer.Flip = Not _imageViewer.Flip

using Leadtools;
using Leadtools.Controls;
using Leadtools.Codecs;
using Leadtools.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;

if (_firstCall)
{
   _firstCall = false;
   // Subscribe to PropertyChanged event
   _imageViewer.PropertyChanged += (sender, e) =>
   {
      if (e.PropertyName == "Flip")
      {
         if (_imageViewer.Flip)
            _label.Text = "Image is flipped";
         else
            _label.Text = "Image is not flipped";
      }
   };
}
// Change the flip state of the image
_imageViewer.Flip = !_imageViewer.Flip;

Target Platforms

Reference

ImageViewer Class
ImageViewer Members