RedirectRead Event (original) (raw)
Summary
Replaces the normal LEADTOOLS method for reading from a file.
Syntax
synchronized public void addRedirectReadListener(CodecsRedirectReadListener listener)
synchronized public void removeRedirectReadListener(CodecsRedirectReadListener listener)
public:
event EventHandler<CodecsRedirectReadEventArgs^>^ RedirectRead
def RedirectRead(sender,e): # sender: RasterCodecs e: CodecsRedirectReadEventArgs Event Data
The event handler receives an argument of type CodecsRedirectReadEventArgs containing data related to this event. The following CodecsRedirectReadEventArgs properties provide information specific to this event.
| Property | Description |
|---|---|
| Buffer | Gets a pointer to the unmanaged memory buffer into which this read operation should copy the data. |
Example
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;
using Leadtools.Svg;
// Redirect Read event example
FileStream myStream;
// Redirect Open event example
private void Codecs_Open(object sender, CodecsRedirectOpenEventArgs e)
{
myStream = new FileStream(e.FileName, e.Mode);
Console.WriteLine("Access: {0}, Share: {1}", e.Access, e.Share);
e.Success = true;
}
// Redirect Seek event example
private void Codecs_Seek(object sender, CodecsRedirectSeekEventArgs e)
{
myStream.Seek(e.Offset, e.Origin);
e.Offset = myStream.Position;
}
// Redirect Read event example
private void Codecs_Read(object sender, CodecsRedirectReadEventArgs e)
{
byte[] byteBuffer = new byte[e.Count];
myStream.Read(byteBuffer, 0, e.Count);
Marshal.Copy(byteBuffer, 0, e.Buffer, e.Count);
e.Read = e.Count;
Debug.WriteLine("The number of bytes that read request should copy to the buffer is : {0}", e.Count);
Debug.WriteLine("The actual number of bytes that this read request has copied to Buffer is : {0}", e.Read);
}
// Redirect Write event example
private void Codecs_Write(object sender, CodecsRedirectWriteEventArgs e)
{
byte[] byteBuffer = new byte[e.Count];
Marshal.Copy(e.Buffer, byteBuffer, 0, e.Count);
myStream.Write(byteBuffer, 0, e.Count);
e.Written = e.Count;
Debug.WriteLine("The number of bytes that write request should copy from the buffer is : {0}", e.Count);
Debug.WriteLine("The actual number of bytes that this write request has copied from Buffer is : {0}", e.Written);
}
// Redirect Close event example
private void Codecs_Close(object sender, CodecsRedirectCloseEventArgs e)
{
myStream.Close();
}
public void StartRedirectingExample()
{
RasterCodecs codecs = new RasterCodecs();
codecs.RedirectOpen += new EventHandler<CodecsRedirectOpenEventArgs>(Codecs_Open);
codecs.RedirectSeek += new EventHandler<CodecsRedirectSeekEventArgs>(Codecs_Seek);
codecs.RedirectRead += new EventHandler<CodecsRedirectReadEventArgs>(Codecs_Read);
codecs.RedirectWrite += new EventHandler<CodecsRedirectWriteEventArgs>(Codecs_Write);
codecs.RedirectClose += new EventHandler<CodecsRedirectCloseEventArgs>(Codecs_Close);
string srcFilename = Path.Combine(LEAD_VARS.ImagesDir, "test_image1.cmp");
codecs.StartRedirecting();
RasterImage image = codecs.Load(srcFilename);
myStream.Close();
codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Image1_redirect.jpg"), RasterImageFormat.Jpeg, image.BitsPerPixel);
codecs.StopRedirecting();
// Clean up
myStream.Dispose();
image.Dispose();
codecs.Dispose();
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}
Leadtools.Codecs Assembly
CompactFile(Stream,Stream,int,int,bool,int,int,bool,int,CodecsSavePageMode,bool,bool) Method
CompactFile(Stream,Stream,int,int,bool,long,int,bool,long,CodecsSavePageMode,bool,bool,bool) Method
CompactFile(string,string,int,int,bool,int,int,bool,int,CodecsSavePageMode,bool,bool) Method
CompactFile(string,string,int,int,bool,long,int,bool,long,CodecsSavePageMode,bool,bool,bool) Method