生成缩略图

using  System;
using  System.Data;
using  System.Configuration;
using  System.Web;
using  System.Web.Security;
using  System.Web.UI;
using  System.Web.UI.HtmlControls;
using  System.Web.UI.WebControls;
using  System.Web.UI.WebControls.WebParts;
using  System.Drawing;

public   class  PictureSlightly
{
     public  PictureSlightly()
    {
         //
         //  TODO: Add constructor logic here
         //
    }
     ///   <summary>
     ///  生成缩略图
     ///   </summary>
     ///   <param name="SourceImage"> 源图路径(含图片，物理路径) </param>
     ///   <param name="ImageMapth"> 缩略图路径（含图片，物理路径) </param>
     ///   <param name="width"> 缩略图宽 </param>
     ///   <param name="height"> 缩略图高 </param>
     public   static   void  MakeImage( string  sourceImage,  string  imageMapth,  int  width,  int  height,  string  mode)
    {
        System.Drawing.Image MyImage  =  System.Drawing.Image.FromFile(sourceImage);
         int  towidth  =  width;
         int  toheight  =  height;
         int  x  =   0 , y  =   0 ;
         int  ow  =  MyImage.Width;
         int  oh  =  MyImage.Height;
         switch  (mode)
        {
             case   " hw " :  break ;
             case   " w " : toheight  =  MyImage.Height  *  width  /  MyImage.Width;  break ;
             case   " h " : towidth  =  MyImage.Width  *  height  /  MyImage.Height;  break ;
             case   " cut " :
                 if  (( double )MyImage.Width  /  ( double )MyImage.Height  >  ( double )towidth  /  ( double )toheight)
                {
                    oh  =  MyImage.Height;
                    ow  =  MyImage.Width  *  towidth  /  toheight;
                    y  =   0 ;
                    x  =  (MyImage.Width  -  ow)  /   2 ;
                }
                 else
                {
                    ow  =  MyImage.Width;
                    oh  =  MyImage.Height  *  height  /  toheight;
                    x  =   0 ;
                    y  =  (MyImage.Height  -  oh)  /   2 ;
                };  break ;
             default :  break ;
        }

        System.Drawing.Image bitmap  =   new  System.Drawing.Bitmap(towidth, toheight);
        Graphics g  =  Graphics.FromImage(bitmap);
        g.InterpolationMode  =  System.Drawing.Drawing2D.InterpolationMode.High;
        g.SmoothingMode  =  System.Drawing.Drawing2D.SmoothingMode.HighQuality;
        g.Clear(Color.Transparent);
        g.DrawImage(MyImage,  new  Rectangle( 0 ,  0 , towidth, toheight),  new  Rectangle(x, y, ow, oh), GraphicsUnit.Pixel);
         try
        {
            bitmap.Save(imageMapth, System.Drawing.Imaging.ImageFormat.Jpeg);
        }
         catch
        {
        }
        MyImage.Dispose();
        bitmap.Dispose();
        g.Dispose();
    }
}