Changed Event

Occurs when the image data or attributes has changed.

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public event EventHandler<RasterImageChangedEventArgs> Changed

'Declaration
 
Public Event Changed As EventHandler(Of RasterImageChangedEventArgs)

'Usage
 
Dim instance As RasterImage
Dim handler As EventHandler(Of RasterImageChangedEventArgs)
 
AddHandler instance.Changed, handler

public event EventHandler<RasterImageChangedEventArgs> Changed

add_Changed(function(sender, e))
remove_Changed(function(sender, e))

public:
event EventHandler<RasterImageChangedEventArgs^>^ Changed

Event Data

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

Property	Description
Flags	Gets the flags for the Changed event.

Remarks

When the data or attributes of a RasterImage object changes, the Changed event is fired with information of what has changed. For example, you can subscribe to this event to get notified when the RasterImage object has been changed and need to be updated in your user interface by re-painting it.

For more information, refer to RasterImageChangedEventArgs.

Example

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

Public Sub ChangedExample()
      Dim codecs As RasterCodecs = New RasterCodecs()

      Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")

      ' Load the image
      Dim img As RasterImage = codecs.Load(srcFileName)

      ' Subscribe to the Changed event of this image
      AddHandler img.Changed, AddressOf img_Changed

      ' Call a few methods and image processing commands that changes the image
      Console.WriteLine("Calling FlipViewPerspective")
      img.FlipViewPerspective(True)

      Console.WriteLine("Calling RotateViewPerspective")
      img.RotateViewPerspective(90)

      Console.WriteLine("Calling FlipCommand")
      Dim flip As FlipCommand = New FlipCommand(True)
      flip.Run(img)

      ' Now disable firing the events and call the methods again
      Console.WriteLine("Disabling the events")
      img.DisableEvents()

      Console.WriteLine("Calling FlipViewPerspective")
      img.FlipViewPerspective(True)

      Console.WriteLine("Calling RotateViewPerspective")
      img.RotateViewPerspective(90)

      Console.WriteLine("Calling FlipCommand while")
      flip.Run(img)

      ' Re-enable the events and fire it manually
      Console.WriteLine("Re-enabling the events")
      img.EnableEvents()

      Console.WriteLine("Firing the event manually")
      Dim flags As RasterImageChangedFlags = RasterImageChangedFlags.Data Or RasterImageChangedFlags.ViewPerspective
      Dim e As RasterImageChangedEventArgs = New RasterImageChangedEventArgs(flags)

      img.OnChanged(e)

      ' Clean up
      RemoveHandler img.Changed, AddressOf img_Changed
      img.Dispose()
      codecs.Dispose()
   End Sub

   Private Sub img_Changed(ByVal sender As Object, ByVal e As RasterImageChangedEventArgs)
      ' Show the changed flags
      Console.WriteLine("Changed: {0}", e.Flags)
   End Sub

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

public void ChangedExample()
   {
      RasterCodecs codecs = new RasterCodecs();

      string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp");

      // Load the image
      RasterImage img = codecs.Load(srcFileName);

      // Subscribe to the Changed event of this image
      img.Changed += new EventHandler<RasterImageChangedEventArgs>(img_Changed);

      // Call a few methods and image processing commands that changes the image
      Console.WriteLine("Calling FlipViewPerspective");
      img.FlipViewPerspective(true);

      Console.WriteLine("Calling RotateViewPerspective");
      img.RotateViewPerspective(90);

      Console.WriteLine("Calling FlipCommand");
      FlipCommand flip = new FlipCommand(true);
      flip.Run(img);

      // Now disable firing the events and call the methods again
      Console.WriteLine("Disabling the events");
      img.DisableEvents();

      Console.WriteLine("Calling FlipViewPerspective");
      img.FlipViewPerspective(true);

      Console.WriteLine("Calling RotateViewPerspective");
      img.RotateViewPerspective(90);

      Console.WriteLine("Calling FlipCommand while");
      flip.Run(img);

      // Re-enable the events and fire it manually
      Console.WriteLine("Re-enabling the events");
      img.EnableEvents();

      Console.WriteLine("Firing the event manually");
      RasterImageChangedFlags flags = RasterImageChangedFlags.Data | RasterImageChangedFlags.ViewPerspective;
      RasterImageChangedEventArgs e = new RasterImageChangedEventArgs(flags);

      img.OnChanged(e);

      // Clean up
      img.Changed -= new EventHandler<RasterImageChangedEventArgs>(img_Changed);
      img.Dispose();
      codecs.Dispose();
   }

   void img_Changed(object sender, RasterImageChangedEventArgs e)
   {
      // Show the changed flags
      Console.WriteLine("Changed: {0}", e.Flags);
   }

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

RasterImageExamples.prototype.ChangedExample = function ()
{
   Tools.SetLicense();
   with ( Leadtools ) 
   {
      with (Leadtools.Codecs) {
         var codecs = new RasterCodecs();

         var srcFileName = "Assets\\Image1.cmp";

         // Load the image
         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {

            return codecs.loadAsync(LeadStreamFactory.create(loadFile));
         })
            .then(function (img) {

               // Subscribe to the Changed event of this image
               
               img.addEventListener("changed", img_Changed);

               // Call a few methods and image processing commands that changes the image
               console.info("Calling FlipViewPerspective");
               img.flipViewPerspective(true);

               console.info("Calling RotateViewPerspective");
               img.rotateViewPerspective(90);

               console.info("Calling FlipCommand");
               var flip = new Leadtools.ImageProcessing.FlipCommand(true);
               flip.run(img);

               // Now disable firing the events and call the methods again
               console.info("Disabling the events");
               img.disableEvents();

               console.info("Calling FlipViewPerspective");
               img.flipViewPerspective(true);

               console.info("Calling RotateViewPerspective");
               img.rotateViewPerspective(90);

               console.info("Calling FlipCommand while");
               flip.run(img);

               // Re-enable the events and fire it manually
               console.info("Re-enabling the events");
               img.enableEvents();

               console.info("Firing the event manually");
               var flags = RasterImageChangedFlags.data | RasterImageChangedFlags.viewPerspective;
               var e = new RasterImageChangedEventArgs(flags);

               img.onChanged(e);

               // Clean up
               img.removeEventListener ( "changed", img_Changed);
               img.close();
               codecs.close();
            },
            function (error) { HandleError(error); });
      }
   }
}

function img_Changed(args)
{
   // Show the changed flags
   console.info("Changed: ", args.flags);
}

[TestMethod]
public async Task ChangedExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = @"Assets\Image1.cmp";

   // Load the image
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage img = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Subscribe to the Changed event of this image
   img.Changed += new EventHandler<RasterImageChangedEventArgs>(img_Changed);

   // Call a few methods and image processing commands that changes the image
   Debug.WriteLine("Calling FlipViewPerspective");
   img.FlipViewPerspective(true);

   Debug.WriteLine("Calling RotateViewPerspective");
   img.RotateViewPerspective(90);

   Debug.WriteLine("Calling FlipCommand");
   FlipCommand flip = new FlipCommand(true);
   flip.Run(img);

   // Now disable firing the events and call the methods again
   Debug.WriteLine("Disabling the events");
   img.DisableEvents();

   Debug.WriteLine("Calling FlipViewPerspective");
   img.FlipViewPerspective(true);

   Debug.WriteLine("Calling RotateViewPerspective");
   img.RotateViewPerspective(90);

   Debug.WriteLine("Calling FlipCommand while");
   flip.Run(img);

   // Re-enable the events and fire it manually
   Debug.WriteLine("Re-enabling the events");
   img.EnableEvents();

   Debug.WriteLine("Firing the event manually");
   RasterImageChangedFlags flags = RasterImageChangedFlags.Data | RasterImageChangedFlags.ViewPerspective;
   RasterImageChangedEventArgs e = new RasterImageChangedEventArgs(flags);

   img.OnChanged(e);

   // Clean up
   img.Changed -= new EventHandler<RasterImageChangedEventArgs>(img_Changed);
   img.Dispose();
   codecs.Dispose();
}

void img_Changed(object sender, RasterImageChangedEventArgs e)
{
   // Show the changed flags
   Debug.WriteLine("Changed: {0}", e.Flags);
}

public void ChangedExample()
{
   // create a new image to work with
   RasterImage img = new RasterImage(RasterMemoryFlags.Conventional, 500, 500, 24, RasterByteOrder.Bgr, RasterViewPerspective.TopLeft, null, null, 0);
   // Subscribe to the Changed event of this image
   img.Changed += new EventHandler<RasterImageChangedEventArgs>(img_Changed);

   // Call a few methods and image processing commands that changes the image
   Debug.WriteLine("Calling FlipViewPerspective");
   img.FlipViewPerspective(true);

   Debug.WriteLine("Calling RotateViewPerspective");
   img.RotateViewPerspective(90);

   Debug.WriteLine("Calling FlipCommand");
   FlipCommand flip = new FlipCommand(true);
   flip.Run(img);

   // Now disable firing the events and call the methods again
   Debug.WriteLine("Disabling the events");
   img.DisableEvents();

   Debug.WriteLine("Calling FlipViewPerspective");
   img.FlipViewPerspective(true);

   Debug.WriteLine("Calling RotateViewPerspective");
   img.RotateViewPerspective(90);

   Debug.WriteLine("Calling FlipCommand while");
   flip.Run(img);

   // Re-enable the events and fire it manually
   Debug.WriteLine("Re-enabling the events");
   img.EnableEvents();

   Debug.WriteLine("Firing the event manually");
   RasterImageChangedFlags flags = RasterImageChangedFlags.Data | RasterImageChangedFlags.ViewPerspective;
   RasterImageChangedEventArgs e = new RasterImageChangedEventArgs(flags);

   img.OnChanged(e);

   // Clean up
   img.Changed -= new EventHandler<RasterImageChangedEventArgs>(img_Changed);
   img.Dispose();
}

void img_Changed(object sender, RasterImageChangedEventArgs e)
{
   // Show the changed flags
   Debug.WriteLine("Changed: {0}", e.Flags);
}

Public Sub ChangedExample()
   ' create a new image to work with
   Dim img As RasterImage = New RasterImage(RasterMemoryFlags.Conventional, 500, 500, 24, RasterByteOrder.Bgr, RasterViewPerspective.TopLeft, Nothing, Nothing, 0)
   ' Subscribe to the Changed event of this image
   AddHandler img.Changed, AddressOf img_Changed

   ' Call a few methods and image processing commands that changes the image
   Debug.WriteLine("Calling FlipViewPerspective")
   img.FlipViewPerspective(True)

   Debug.WriteLine("Calling RotateViewPerspective")
   img.RotateViewPerspective(90)

   Debug.WriteLine("Calling FlipCommand")
   Dim flip As FlipCommand = New FlipCommand(True)
   flip.Run(img)

   ' Now disable firing the events and call the methods again
   Debug.WriteLine("Disabling the events")
   img.DisableEvents()

   Debug.WriteLine("Calling FlipViewPerspective")
   img.FlipViewPerspective(True)

   Debug.WriteLine("Calling RotateViewPerspective")
   img.RotateViewPerspective(90)

   Debug.WriteLine("Calling FlipCommand while")
   flip.Run(img)

   ' Re-enable the events and fire it manually
   Debug.WriteLine("Re-enabling the events")
   img.EnableEvents()

   Debug.WriteLine("Firing the event manually")
   Dim flags As RasterImageChangedFlags = RasterImageChangedFlags.Data Or RasterImageChangedFlags.ViewPerspective
   Dim e As RasterImageChangedEventArgs = New RasterImageChangedEventArgs(flags)

   img.OnChanged(e)

   ' Clean up
   RemoveHandler img.Changed, AddressOf img_Changed
   img.Dispose()
End Sub

Private Sub img_Changed(ByVal sender As Object, ByVal e As RasterImageChangedEventArgs)
   ' Show the changed flags
   Debug.WriteLine("Changed: {0}", e.Flags)
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

RasterImage Class
RasterImage Members