LoadPage Event

Occurs multiple times for each page loaded from an image file.

Syntax

public event EventHandler<CodecsPageEventArgs> LoadPage

public event EventHandler<CodecsPageEventArgs> LoadPage

add_LoadPage(function(sender, e))
remove_LoadPage(function(sender, e))

public:
event EventHandler<CodecsPageEventArgs^>^ LoadPage

'Declaration
 
Public Event LoadPage As EventHandler(Of CodecsPageEventArgs)

'Usage
 
Dim instance As RasterCodecs
Dim handler As EventHandler(Of CodecsPageEventArgs)
 
AddHandler instance.LoadPage, handler

Event Data

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

Property	Description
Command	Gets or sets a value indicating how the load or save process should continue.
FileName	Gets the name of the file being loaded or saved.
Image	Gets the object being loaded from the image file page or the image that is being saved.
Page	Gets the page number of the image being loaded or saved.
PageCount	Gets the number of pages being loaded or saved.
State	Gets the state of the load or save process.
Stream	Gets the stream used by the load process.

Remarks

This event will fire multiple times for each page loaded with any of the Load(String) and LoadAsync(String,LeadRect,Int32,CodecsLoadByteOrder,Int32,Int32,Object) methods. The user should check the CodecsPageEventArgs.State property. You can use this event to get information about the image pages being loaded or to skip loading certain pages.

Example

Private Sub Codecs_LoadSavePage(ByVal sender As Object, ByVal e As CodecsPageEventArgs)
      If e.State = CodecsPageEventState.After Then
         Console.WriteLine("The image has been processed")
      Else
         Console.WriteLine("The image has not processed yet")
      End If
      If e.Page > 5 Then
         e.Command = CodecsPageEventCommand.Stop
      End If

      Console.WriteLine("File name is: {0}", e.FileName)
      If Not e.Image Is Nothing Then
         Console.WriteLine("The Image width and height is: {0},{1}", e.Image.Width, e.Image.Height)
      End If
      Console.WriteLine("Page Index is: {0}", e.Page)
      Console.WriteLine("Page Count is: {0}", e.PageCount)
   End Sub


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

      AddHandler codecs.LoadPage, AddressOf Codecs_LoadSavePage
      AddHandler codecs.SavePage, AddressOf Codecs_LoadSavePage

      Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"))
      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "loadsave.jpg"), RasterImageFormat.Jpeg, image.BitsPerPixel)

      RemoveHandler codecs.LoadPage, AddressOf Codecs_LoadSavePage
      RemoveHandler codecs.SavePage, AddressOf Codecs_LoadSavePage

      ' Clean up
      codecs.Dispose()
      image.Dispose()
   End Sub

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

private void Codecs_LoadSavePage(object sender, CodecsPageEventArgs e)
     {
         if (e.State == CodecsPageEventState.After)
             Console.WriteLine("The image has been processed");
         else
             Console.WriteLine("The image has not processed yet");
         if (e.Page > 5)
             e.Command = CodecsPageEventCommand.Stop;

         Console.WriteLine("File name is: {0}", e.FileName);
         if (e.Image != null)
             Console.WriteLine("The Image width and height is: {0},{1}", e.Image.Width, e.Image.Height);
         Console.WriteLine("Page Index is: {0}", e.Page);
         Console.WriteLine("Page Count is: {0}", e.PageCount);
     }

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

         codecs.LoadPage += new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);
         codecs.SavePage += new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);

         RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"));
         codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "loadsave.jpg"), RasterImageFormat.Jpeg, image.BitsPerPixel);

         codecs.LoadPage -= new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);
         codecs.SavePage -= new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);

         // Clean up
         codecs.Dispose();
         image.Dispose();
     }

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

function Codecs_LoadSavePage(e)
{
   if (e.state == Leadtools.Codecs.CodecsPageEventState.after)
      console.info("The image has been processed");
   else
      console.info("The image has not processed yet");

   if (e.page > 5)
      e.command = Leadtools.Codecs.CodecsPageEventCommand.stop;

   if (e.image != null)
      console.info("The Image width and height is: ", e.image.width, " , ", e.image.height);
   console.info("Page Index is: ", e.page);
   console.info("Page Count is: ", e.pageCount);
}

RasterCodecsExamples.prototype.LoadPageExample = function () {
   Tools.SetLicense();
   with (Leadtools) {
      with (Leadtools.Codecs) {
         var codecs = new RasterCodecs();
         var image;
         Leadtools.RasterSupport.initialize();
         codecs.eventsDispatchMode = Leadtools.LeadEventsDispatchMode.useCoreDispatcher;

         codecs.addEventListener("loadpage", Codecs_LoadSavePage);
         codecs.addEventListener("savepage", Codecs_LoadSavePage);

         var srcFileName = "Assets\\Image1.cmp";
         var destFileName = "loadsave.jpg";
         var image;
         console.info("Loading...");
         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile))
         })
            .then(function (img) {
               image = img;

               console.info("Saving...");
               return Tools.AppLocalFolder().createFileAsync(destFileName)
            })
            .then(function (saveFile) {
               return codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.jpeg, image.bitsPerPixel)
            })
            .then(function () {
               codecs.removeEventListener("loadPage", Codecs_LoadSavePage);
               codecs.removeEventListener("savePage", Codecs_LoadSavePage);

               // Clean up
               codecs.close();
               image.close();
            });
      }
   }
}

private void Codecs_LoadSavePage(object sender, CodecsPageEventArgs e)
{
   if (e.State == CodecsPageEventState.After)
      Debug.WriteLine("The image has been processed");
   else
      Debug.WriteLine("The image has not processed yet");
   if (e.Page > 5)
      e.Command = CodecsPageEventCommand.Stop;

   if (e.Image != null)
      Debug.WriteLine("The Image width and height is: {0},{1}", e.Image.Width, e.Image.Height);
   Debug.WriteLine("Page Index is: {0}", e.Page);
   Debug.WriteLine("Page Count is: {0}", e.PageCount);
}

[TestMethod]
public async Task LoadPageExample()
{
   RasterCodecs codecs = new RasterCodecs();

   codecs.LoadPage += new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);
   codecs.SavePage += new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);

   string srcFileName = @"Assets\Image1.cmp";
   string destFileName = @"loadsave.jpg";

   Debug.WriteLine("Loading...");
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   Debug.WriteLine("Saving...");
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Jpeg, image.BitsPerPixel);

   codecs.LoadPage -= new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);
   codecs.SavePage -= new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);

   // Clean up
   codecs.Dispose();
   image.Dispose();
}

private void Codecs_LoadSavePage(object sender, CodecsPageEventArgs e)
{
   if(e.State == CodecsPageEventState.After)
      Debug.WriteLine("The image has been processed");
   else
      Debug.WriteLine("The image has not processed yet");
   if(e.Page > 5)
      e.Command = CodecsPageEventCommand.Stop;

   Debug.WriteLine("File name is: {0}", e.FileName);
   if(e.Image != null)
      Debug.WriteLine("The Image width and height is: {0},{1}", e.Image.Width, e.Image.Height);
   Debug.WriteLine("Page Index is: {0}", e.Page);
   Debug.WriteLine("Page Count is: {0}", e.PageCount);
}

public void LoadPageExample(Stream inStream, Stream outStream)
{
   RasterCodecs codecs = new RasterCodecs();

   codecs.LoadPage += new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);
   codecs.SavePage += new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);

   RasterImage image = codecs.Load(inStream);

   codecs.Save(image, outStream, RasterImageFormat.Jpeg, image.BitsPerPixel);

   codecs.LoadPage -= new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);
   codecs.SavePage -= new EventHandler<CodecsPageEventArgs>(Codecs_LoadSavePage);

   // Clean up
   image.Dispose();
}

Private Sub Codecs_LoadSavePage(ByVal sender As Object, ByVal e As CodecsPageEventArgs)
   If e.State = CodecsPageEventState.After Then
      Debug.WriteLine("The image has been processed")
   Else
      Debug.WriteLine("The image has not processed yet")
   End If
   If e.Page > 5 Then
      e.Command = CodecsPageEventCommand.Stop
   End If

   Debug.WriteLine("File name is: {0}", e.FileName)
   If Not e.Image Is Nothing Then
      Debug.WriteLine("The Image width and height is: {0},{1}", e.Image.Width, e.Image.Height)
   End If
   Debug.WriteLine("Page Index is: {0}", e.Page)
   Debug.WriteLine("Page Count is: {0}", e.PageCount)
End Sub

Public Sub LoadPageExample(ByVal inStream As Stream, ByVal outStream As Stream)
   Dim codecs As RasterCodecs = New RasterCodecs()

   AddHandler codecs.LoadPage, AddressOf Codecs_LoadSavePage
   AddHandler codecs.SavePage, AddressOf Codecs_LoadSavePage

   Dim image As RasterImage = codecs.Load(inStream)

   codecs.Save(image, outStream, RasterImageFormat.Jpeg, image.BitsPerPixel)

   RemoveHandler codecs.LoadPage, AddressOf Codecs_LoadSavePage
   RemoveHandler codecs.SavePage, AddressOf Codecs_LoadSavePage

   ' Clean up
   image.Dispose()
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

RasterCodecs Class
RasterCodecs Members