AutoDisposeImages Property (RasterImageViewer)

Visual Basic
C#
Objective-C
Java
C++

public bool AutoDisposeImages {get; set;}

'Declaration
 
Public Property AutoDisposeImages As Boolean

'Usage
 
Dim instance As RasterImageViewer
Dim value As Boolean
 
instance.AutoDisposeImages = value
 
value = instance.AutoDisposeImages

public:
property bool AutoDisposeImages {
   bool get();
   void set (    bool value);
}

Property Value

true if the Leadtools.RasterImage object in Image is automatically disposed when a new image is set; otherwise, false. Default value is true.

By default, whenever you set a new Leadtools.RasterImage object into the Image property, the old image (if any) is disposed. Set the value of this property to false to prevent disposing of the old image.

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

Copy Code

Imports Leadtools.Windows.Controls
Imports Leadtools.ImageProcessing
Imports Leadtools.Codecs
Imports Leadtools

Public Sub RasterImageViewer_AutoDisposeImages(ByVal viewer As RasterImageViewer)
   ' Load two image2 
   Dim codecs As New RasterCodecs()
   Dim file1 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
   Dim file2 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image2.cmp")
   AddHandler viewer.ImageChanged, AddressOf viewer_ImageChanged

   Dim image1 As RasterImage = codecs.Load(file1)
   Dim image2 As RasterImage = codecs.Load(file2)

   ' Make sure the AutoDisposeImages property of the viewer is set to true 
   viewer.AutoDisposeImages = True

   ' Set the first image into the viewer
   viewer.Image = image1

   ' Now set the second image into the viewer (this disposes the first image since the AutoDisposeImages property is true)
   viewer.Image = image2

   ' Try to access the first image, it generates a NullReferenceException exception since the image has been disposed 
   MessageBox.Show("Try to access the first image, it generates a NullReferenceException exception since the image has been disposed.")
   Try
      Dim width As Integer = image1.Width
      MessageBox.Show(String.Format("Width is {0} pixels", width))
   Catch ex As NullReferenceException
      MessageBox.Show(ex.Message)
   End Try

   ' Set the image to Nothing (will dispose the second image as well)
   viewer.Image = Nothing

   ' Now re-load the two images
   image1 = codecs.Load(file1)
   image2 = codecs.Load(file2)

   ' Make sure the AutoDisposeImages property of the viewer is set to false 
   viewer.AutoDisposeImages = False

   ' Set the first image into the viewer 
   viewer.Image = image1

   ' Now set the second image into the viewer (this will not disposes the first image since the AutoDisposeImages property is false) 
   viewer.Image = image2

   ' Try to access the first image, it should work fine this time 
   Try
      Dim width As Integer = image1.Width
      MessageBox.Show(String.Format("Width is {0} pixels", width))
   Catch ex As NullReferenceException
      MessageBox.Show(ex.Message)
   End Try

   ' Set the image to Nothing (will not dispose the second image) 
   viewer.Image = Nothing

   ' We should now dispose the two images manually
   image1.Dispose()
   image2.Dispose()
   codecs.Dispose()

   RemoveHandler viewer.ImageChanged, AddressOf viewer_ImageChanged
End Sub

Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

using Leadtools.Help;
using Leadtools.Windows.Controls;
using Leadtools.ImageProcessing;
using Leadtools.Codecs;

public void RasterImageViewer_AutoDisposeImages(RasterImageViewer viewer)
{
   // Load two image2 
   RasterCodecs codecs = new RasterCodecs();
   string file1 = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp");
   string file2 = Path.Combine(LEAD_VARS.ImagesDir, "Image2.cmp");
   viewer.ImageChanged += new RoutedPropertyChangedEventHandler<RasterImage>(viewer_ImageChanged);

   RasterImage image1 = codecs.Load(file1);
   RasterImage image2 = codecs.Load(file2);

   // Make sure the AutoDisposeImages property of the viewer is set to true 
   viewer.AutoDisposeImages = true;

   // Set the first image into the viewer 
   viewer.Image = image1;

   // Now set the second image into the viewer (this disposes the first image since the AutoDisposeImages property is true) 
   viewer.Image = image2;

   // Try to access the first image, it generates a NullReferenceException exception since the image has been disposed 
   MessageBox.Show("Try to access the first image, it generates a NullReferenceException exception since the image has been disposed.");
   try
   {
      int width = image1.Width;
      MessageBox.Show(string.Format("Width is {0} pixels", width));
   }
   catch (NullReferenceException ex)
   {
      MessageBox.Show(ex.Message);
   }

   // Set the image to null (will dispose the second image as well) 
   viewer.Image = null;

   // Now re-load the two images 
   image1 = codecs.Load(file1);
   image2 = codecs.Load(file2);

   // Make sure the AutoDisposeImages property of the viewer is set to false 
   viewer.AutoDisposeImages = false;

   // Set the first image into the viewer 
   viewer.Image = image1;

   // Now set the second image into the viewer (this will not disposes the first image since the AutoDisposeImages property is false) 
   viewer.Image = image2;

   // Try to access the first image, it should work fine this time 
   try
   {
      int width = image1.Width;
      MessageBox.Show(string.Format("Width is {0} pixels", width));
   }
   catch (NullReferenceException ex)
   {
      MessageBox.Show(ex.Message);
   }

   // Set the image to null (will not dispose the second image) 
   viewer.Image = null;

   // We should now dispose the two images manually 
   image1.Dispose();
   image2.Dispose();
   codecs.Dispose();

   viewer.ImageChanged -= new RoutedPropertyChangedEventHandler<RasterImage>(viewer_ImageChanged);
}

static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

Target Platforms

Reference

RasterImageViewer Class
RasterImageViewer Members