asp.net instance source code for generating thumbnails

Using System;

Using System.Data;

Using System.Configuration;

Using System.Web;

Using System.Web.Security;

Using System.Web.UI;

Using System.Web.UI.WebControls;

Using System.Web.UI.WebControls.WebParts;

Using System.Web.UI.HtmlControls;

Using System.IO;

Using System.Drawing;

Using System.Drawing.Imaging;

///

Picture Processing class

1. Generate thumbnail images or change the size and quality of pictures proportionally

2. Place the generated thumbnail in the specified directory

///

public class Imageclass

{

Public System.Drawing.Image Resourceimage;

private int imagewidth;

private int imageheight;

public string errmessage;

///

Constructors for classes

///

Full path name of picture file

Public Imageclass (String imagefilename)

{

Resourceimage = System.Drawing.Image.FromFile (imagefilename);

Errmessage = "";

}

public bool Thumbnailcallback ()

{

return false;

}

///

Generate thumbnail overload Method 1, returning the image object of the thumbnail

///

width of thumbnails

The height of the thumbnail

Image object for thumbnail image

Public System.Drawing.Image getreducedimage (int Width, int Height)

{

Try

{

System.Drawing.Image Reducedimage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort ( Thumbnailcallback);

Reducedimage = Resourceimage.getthumbnailimage (Width, Height, CALLB, IntPtr.Zero);

return reducedimage;

}

catch (Exception e)

{

Errmessage = E.message;

return null;

}

}

///

Generate thumbnail overload Method 2, save the thumbnail file to the specified path

///

width of thumbnails

The height of the thumbnail

Thumbnail saved full-text name, (with path), parameter format: D:images ilename.jpg

Returns true successfully, otherwise returns false

public bool Getreducedimage (int Width, int Height, string targetfilepath)

{

Try

{

System.Drawing.Image Reducedimage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort ( Thumbnailcallback);

Reducedimage = Resourceimage.getthumbnailimage (Width, Height, CALLB, IntPtr.Zero);

Reducedimage.save (@targetFilePath, imageformat.jpeg);

Reducedimage.dispose ();

return true;

}

catch (Exception e)

{

Errmessage = E.message;

return false;

}

}

///

Generate thumbnail overload Method 3, returning the image object of the thumbnail

///

Percentage of the width of the thumbnail: 80 is required, 0.8.

Image object for thumbnail image

Public System.Drawing.Image getreducedimage (double Percent)

{

Try

{

System.Drawing.Image Reducedimage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort ( Thumbnailcallback);

ImageWidth = Convert.ToInt32 (Resourceimage.width * Percent);

ImageHeight = Convert.ToInt32 (Resourceimage.width * Percent);

Reducedimage = Resourceimage.getthumbnailimage (ImageWidth, ImageHeight, CALLB, IntPtr.Zero);

return reducedimage;

}

catch (Exception e)

{

Errmessage = E.message;

return null;

}

}

///

Generate thumbnail overload method 4, returning the image object of the thumbnail

///

Percentage of the width of the thumbnail: 80 is required, 0.8.

Thumbnail saved full-text name, (with path), parameter format: D:images ilename.jpg

Returns true successfully, otherwise returns false

public bool Getreducedimage (double Percent, String targetfilepath)

{

Try

{

System.Drawing.Image Reducedimage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort ( Thumbnailcallback);

ImageWidth = Convert.ToInt32 (Resourceimage.width * Percent);

ImageHeight = Convert.ToInt32 (Resourceimage.width * Percent);

Reducedimage = Resourceimage.getthumbnailimage (ImageWidth, ImageHeight, CALLB, IntPtr.Zero);

Reducedimage.save (@targetFilePath, imageformat.jpeg);

Reducedimage.dispose ();

return true;

}

catch (Exception e)

{

Errmessage = E.message;

return false;

}

}

}