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OnSourceChanged Method

Summary

Syntax

C++

protected virtual void OnSourceChanged( 
   RoutedPropertyChangedEventArgs<ImageViewer> e 
)

  
Protected Overridable Sub OnSourceChanged( _ 
   ByVal e As RoutedPropertyChangedEventArgs(Of ImageViewer) _ 
)

protected: 
virtual void OnSourceChanged(  
   RoutedPropertyChangedEventArgs<ImageViewer^>^ e 
)

Parameters

e
A RoutedPropertyChangedEventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate.

The OnSourceChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors: When overriding OnSourceChanged in a derived class, be sure to call the base class's OnSourceChanged method so that registered delegates receive the event.

Example

Silverlight C#

Silverlight VB

using Leadtools.Help; 
using Leadtools.Windows.Controls; 
 
public void ImagePanViewer_SourceChanged(ImagePanViewer panViewer) 
{ 
   // set up the event handlers 
   panViewer.StrokeChanged += new RoutedPropertyChangedEventHandler<Brush>(panViewer_StrokeChanged); 
   panViewer.SourceChanged += new RoutedPropertyChangedEventHandler<ImageViewer>(panViewer_SourceChanged); 
   panViewer.InnerBrushChanged += new RoutedPropertyChangedEventHandler<Brush>(panViewer_InnerBrushChanged); 
   panViewer.OuterBrushChanged += new RoutedPropertyChangedEventHandler<Brush>(panViewer_OuterBrushChanged); 
   panViewer.PositionChanged += new RoutedPropertyChangedEventHandler<Point>(panViewer_PositionChanged); 
 
   ImageViewer viewerOld = panViewer.Source; 
   // fires the SourceChanged event twice 
   panViewer.Source = null; 
   panViewer.Source = viewerOld; 
 
   // change some properties 
   panViewer.Stroke = Brushes.Black; 
   panViewer.StrokeThickness = 2; 
 
   panViewer.Position = new Point(20, 20); 
} 
 
void panViewer_PositionChanged(object sender, RoutedPropertyChangedEventArgs<Point> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Position Changed to " + panViewer.Position.ToString()); 
} 
 
void panViewer_OuterBrushChanged(object sender, RoutedPropertyChangedEventArgs<Brush> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Inner Brush Changed to " + panViewer.OuterBrush.ToString() + "Color"); 
} 
 
void panViewer_InnerBrushChanged(object sender, RoutedPropertyChangedEventArgs<Brush> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Inner Brush Changed to " + panViewer.InnerBrush.ToString() + "Color"); 
} 
 
private void panViewer_StrokeChanged(object sender, RoutedPropertyChangedEventArgs<Brush> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Rectangle Stroke Changed to " + panViewer.StrokeThickness.ToString() + "Thickness and to" + panViewer.Stroke.ToString() + "Color"); 
} 
 
private void panViewer_SourceChanged(object sender, RoutedPropertyChangedEventArgs<ImageViewer> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
   { 
      if (panViewer.Source == null) 
         Console.WriteLine("There is no Viewer control associated with the ImagePanViewer Control"); 
      else 
         Console.WriteLine("A Viewer is now associated with the ImagePanViewer Control"); 
   } 
}

Imports Leadtools.Windows.Controls 
 
Public Sub ImagePanViewer_SourceChanged(ByVal panViewer As ImagePanViewer) 
   ' set up the event handlers 
   AddHandler panViewer.StrokeChanged, AddressOf panViewer_StrokeChanged 
   AddHandler panViewer.SourceChanged, AddressOf panViewer_SourceChanged 
   AddHandler panViewer.InnerBrushChanged, AddressOf panViewer_InnerBrushChanged 
   AddHandler panViewer.OuterBrushChanged, AddressOf panViewer_OuterBrushChanged 
   AddHandler panViewer.PositionChanged, AddressOf panViewer_PositionChanged 
 
   Dim viewerOld As ImageViewer = panViewer.Source 
   ' fires the SourceChanged event twice 
   panViewer.Source = Nothing 
   panViewer.Source = viewerOld 
 
   ' change some properties 
   panViewer.Stroke = Brushes.Black 
   panViewer.StrokeThickness = 2 
 
   panViewer.Position = New Point(20, 20) 
End Sub 
 
Private Sub panViewer_PositionChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Point)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Position Changed to " & panViewer.Position.ToString()) 
   End If 
End Sub 
 
Private Sub panViewer_OuterBrushChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Brush)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Inner Brush Changed to " & panViewer.OuterBrush.ToString() & "Color") 
   End If 
End Sub 
 
Private Sub panViewer_InnerBrushChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Brush)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Inner Brush Changed to " & panViewer.InnerBrush.ToString() & "Color") 
   End If 
End Sub 
 
Private Sub panViewer_StrokeChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Brush)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Rectangle Stroke Changed to " & panViewer.StrokeThickness.ToString() & "Thickness and to" & panViewer.Stroke.ToString() & "Color") 
   End If 
End Sub 
 
Private Sub panViewer_SourceChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of ImageViewer)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      If panViewer.Source Is Nothing Then 
         Console.WriteLine("There is no Viewer control associated with the ImagePanViewer Control") 
      Else 
         Console.WriteLine("A Viewer is now associated with the ImagePanViewer Control") 
      End If 
   End If 
End Sub

using Leadtools.Help; 
using Leadtools.Windows.Controls; 
 
public void ImagePanViewer_SourceChanged(ImagePanViewer panViewer) 
{ 
   // set up the event handlers 
   panViewer.StrokeChanged += new RoutedPropertyChangedEventHandler<Brush>(panViewer_StrokeChanged); 
   panViewer.SourceChanged += new RoutedPropertyChangedEventHandler<ImageViewer>(panViewer_SourceChanged); 
   panViewer.InnerBrushChanged += new RoutedPropertyChangedEventHandler<Brush>(panViewer_InnerBrushChanged); 
   panViewer.OuterBrushChanged += new RoutedPropertyChangedEventHandler<Brush>(panViewer_OuterBrushChanged); 
   panViewer.PositionChanged += new RoutedPropertyChangedEventHandler<Point>(panViewer_PositionChanged); 
 
   ImageViewer viewerOld = panViewer.Source; 
   // fires the SourceChanged event twice 
   panViewer.Source = null; 
   panViewer.Source = viewerOld; 
 
   // change some properties 
   panViewer.Stroke = new SolidColorBrush(Colors.Black); 
   panViewer.StrokeThickness = 2; 
 
   panViewer.Position = new Point(20, 20); 
} 
 
void panViewer_PositionChanged(object sender, RoutedPropertyChangedEventArgs<Point> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Position Changed to " + panViewer.Position.ToString()); 
} 
 
void panViewer_OuterBrushChanged(object sender, RoutedPropertyChangedEventArgs<Brush> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Inner Brush Changed to " + panViewer.OuterBrush.ToString() + "Color"); 
} 
 
void panViewer_InnerBrushChanged(object sender, RoutedPropertyChangedEventArgs<Brush> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Inner Brush Changed to " + panViewer.InnerBrush.ToString() + "Color"); 
} 
 
private void panViewer_StrokeChanged(object sender, RoutedPropertyChangedEventArgs<Brush> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
      Console.WriteLine("Rectangle Stroke Changed to " + panViewer.StrokeThickness.ToString() + "Thickness and to" + panViewer.Stroke.ToString() + "Color"); 
} 
 
private void panViewer_SourceChanged(object sender, RoutedPropertyChangedEventArgs<ImageViewer> e) 
{ 
   ImagePanViewer panViewer = (ImagePanViewer)sender; 
   if (panViewer != null) 
   { 
      if (panViewer.Source == null) 
         Console.WriteLine("There is no Viewer control associated with the ImagePanViewer Control"); 
      else 
         Console.WriteLine("A Viewer is now associated with the ImagePanViewer Control"); 
   } 
}

Imports Leadtools.Windows.Controls 
 
Public Sub ImagePanViewer_SourceChanged(ByVal panViewer As ImagePanViewer) 
   ' set up the event handlers 
   AddHandler panViewer.StrokeChanged, AddressOf panViewer_StrokeChanged 
   AddHandler panViewer.SourceChanged, AddressOf panViewer_SourceChanged 
   AddHandler panViewer.InnerBrushChanged, AddressOf panViewer_InnerBrushChanged 
   AddHandler panViewer.OuterBrushChanged, AddressOf panViewer_OuterBrushChanged 
   AddHandler panViewer.PositionChanged, AddressOf panViewer_PositionChanged 
 
   Dim viewerOld As ImageViewer = panViewer.Source 
   ' fires the SourceChanged event twice 
   panViewer.Source = Nothing 
   panViewer.Source = viewerOld 
 
   ' change some properties 
   panViewer.Stroke = New SolidColorBrush(Colors.Black) 
   panViewer.StrokeThickness = 2 
 
   panViewer.Position = New Point(20, 20) 
End Sub 
 
Private Sub panViewer_PositionChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Point)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Position Changed to " & panViewer.Position.ToString()) 
   End If 
End Sub 
 
Private Sub panViewer_OuterBrushChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Brush)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Inner Brush Changed to " & panViewer.OuterBrush.ToString() & "Color") 
   End If 
End Sub 
 
Private Sub panViewer_InnerBrushChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Brush)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Inner Brush Changed to " & panViewer.InnerBrush.ToString() & "Color") 
   End If 
End Sub 
 
Private Sub panViewer_StrokeChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Brush)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      Console.WriteLine("Rectangle Stroke Changed to " & panViewer.StrokeThickness.ToString() & "Thickness and to" & panViewer.Stroke.ToString() & "Color") 
   End If 
End Sub 
 
Private Sub panViewer_SourceChanged(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of ImageViewer)) 
   Dim panViewer As ImagePanViewer = CType(sender, ImagePanViewer) 
   If Not panViewer Is Nothing Then 
      If panViewer.Source Is Nothing Then 
         Console.WriteLine("There is no Viewer control associated with the ImagePanViewer Control") 
      Else 
         Console.WriteLine("A Viewer is now associated with the ImagePanViewer Control") 
      End If 
   End If 
End Sub

Requirements

Target Platforms

Reference

ImagePanViewer Class

ImagePanViewer Members

Help Version 19.0.2017.10.27

Leadtools.Windows.Controls Assembly

Introduction

Getting Started

Namespaces

Leadtools.Windows.Controls Namespace

Assemblies