<DescriptionAttribute("Indicating whether to auto dispose the old image when a new image is set into this control")>
<CategoryAttribute("Behavior")>
Public Property AutoDisposeImage As Boolean

Dim instance As RasterPictureBox
Dim value As Boolean
 
instance.AutoDisposeImage = value
 
value = instance.AutoDisposeImage

[DescriptionAttribute("Indicating whether to auto dispose the old image when a new image is set into this control")]
[CategoryAttribute("Behavior")]
public bool AutoDisposeImage {get; set;}

[DescriptionAttribute("Indicating whether to auto dispose the old image when a new image is set into this control")]
[CategoryAttribute("Behavior")]
public:
property bool AutoDisposeImage {
   bool get();
   void set (    bool value);
}

Public Sub RasterPictureBox_AutoDisposeImage(ByVal viewer As RasterPictureBox)
         ' Load two image2
         Dim codecs As RasterCodecs = New RasterCodecs()
         Dim file1 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
         Dim file2 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image2.cmp")


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

         ' Make sure the AutoDisposeImage property of the viewer is set to true
         viewer.AutoDisposeImage = 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 AutoDisposeImage 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 null (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 AutoDisposeImage property of the viewer is set to false
         viewer.AutoDisposeImage = 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 AutoDisposeImage 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 null (will not dispose the second image)
         viewer.Image = Nothing

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

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

public void RasterPictureBox_AutoDisposeImage(RasterPictureBox 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");


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

      // Make sure the AutoDisposeImage property of the viewer is set to true
      viewer.AutoDisposeImage = 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 AutoDisposeImage 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 AutoDisposeImage property of the viewer is set to false
      viewer.AutoDisposeImage = 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 AutoDisposeImage 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();
   }

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