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PropertyChanged Event

Summary

Occurs when a property value in this ImageViewer changes.

Syntax
C#
C++
public event PropertyChangedEventHandler PropertyChanged 
vb[VB Syntax] 
Public Event PropertyChanged As System.ComponentModel.PropertyChangedEventHandler 
public:  
   event System::ComponentModel::PropertyChangedEventHandler^ PropertyChanged 
Remarks

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

Example

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#
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; 
Event Data
ParameterTypeDescription
senderobjectThe source of the event.
eSystem.ComponentModel.PropertyChangedEventArgsThe event data.
Requirements

Target Platforms

Help Version 22.0.2022.4.4
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Leadtools.Controls Assembly

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© 1991-2022 LEAD Technologies, Inc. All Rights Reserved.