LEADTOOLS (Leadtools assembly)

Changed Event

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Example 







Occurs when the image data or attributes has changed.
Syntax
'Declaration
 
Public Event Changed As EventHandler(Of RasterImageChangedEventArgs)
'Usage
 
Dim instance As RasterImage
Dim handler As EventHandler(Of RasterImageChangedEventArgs)
 
AddHandler instance.Changed, handler
NSNotification
    name:LTRasterImageChangedNotification
  object:self
userInfo:NSDictionary
         key:LTRasterImageChangedNotification_flags obj:LTRasterImageChangedFlags (Number)
            
synchronized public void addChangedListener(RasterImageChangedListener listener)
synchronized public void removeChangedListener(RasterImageChangedListener listener)
            
add_Changed(function(sender, e))
remove_Changed(function(sender, e))

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.

PropertyDescription
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
Copy Code  
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.WinForms
Imports Leadtools.Dicom
Imports Leadtools.Drawing

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
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.WinForms;
using Leadtools.Dicom;
using Leadtools.Drawing;

      
public void ChangedExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = Path.Combine(ImagesPath.Path, "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);
}
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);
}
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Dicom;

      
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);
}
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Dicom;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Examples;
using Leadtools.Windows.Media;

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);
}
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Dicom
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.Windows.Media

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

See Also

Reference

RasterImage Class
RasterImage Members

 

 


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