.net 一个图片操作类(封装了以下)

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

namespace EastSoft.BaseClass
...{
     /**//// <summary>
     /// 程序设计：陈文利    QQ：36055915   MSN：sinofishing@hotmail.com
     /// </summary>
     public class ImageMgr
     ...{
         public ImageMgr()
         ...{
             //
             // TODO: 在此处添加构造函数逻辑
             //
         }
         /**//// <summary>
         /// 
         /// </summary>
         /// <param name="originalImagePath"></param>
         /// <param name="thumbnailPath"></param>
         /// <param name="width"></param>
         /// <param name="height"></param>
         /// <param name="mode">"HW"://指定高宽缩放（可能变形）
         /// "W"://指定宽，高按比例  
         /// "H"://指定高，宽按比例
         /// "Cut"://指定高宽裁减（不变形）</param>
         public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
         ...{
             Image originalImage = Image.FromFile(originalImagePath);

             int towidth = width;
             int toheight = height;

             int x = 0;
             int y = 0;
             int ow = originalImage.Width;
             int oh = originalImage.Height;

             switch (mode)
             ...{
                 case "HW"://指定高宽缩放（可能变形）                
                     break;
                 case "W"://指定宽，高按比例                    
                     toheight = originalImage.Height * width / originalImage.Width;
                     break;
                 case "H"://指定高，宽按比例
                     towidth = originalImage.Width * height / originalImage.Height;
                     break;
                 case "Cut"://指定高宽裁减（不变形）                
                     if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                     ...{
                         oh = originalImage.Height;
                         ow = originalImage.Height * towidth / toheight;
                         y = 0;
                         x = (originalImage.Width - ow) / 2;
                     }
                     else
                     ...{
                         ow = originalImage.Width;
                         oh = originalImage.Width * height / towidth;
                         x = 0;
                         y = (originalImage.Height - oh) / 2;
                     }
                     break;
                 default:
                     break;
             }

             //新建一个bmp图片
             Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

             //新建一个画板
             Graphics g = System.Drawing.Graphics.FromImage(bitmap);

             //设置高质量插值法
             g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

             //设置高质量,低速度呈现平滑程度
             g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

             //清空画布并以透明背景色填充
             g.Clear(Color.Transparent);

             //在指定位置并且按指定大小绘制原图片的指定部分
             g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                 new Rectangle(x, y, ow, oh),
                 GraphicsUnit.Pixel);

             try
             ...{
                 //以jpg格式保存缩略图
                 bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
             }
             catch (System.Exception e)
             ...{
                 throw e;
             }
             finally
             ...{
                 originalImage.Dispose();
                 bitmap.Dispose();
                 g.Dispose();
             }
         }


         public static Image RetrunImage(string originalImagePath, string thumbnailPath, int width, int height, string mode)
         ...{
             Image originalImage = Image.FromFile(originalImagePath);

             int towidth = width;
             int toheight = height;

             int x = 0;
             int y = 0;
             int ow = originalImage.Width;
             int oh = originalImage.Height;

             switch (mode)
             ...{
                 case "HW"://指定高宽缩放（可能变形）                
                     break;
                 case "W"://指定宽，高按比例                    
                     toheight = originalImage.Height * width / originalImage.Width;
                     break;
                 case "H"://指定高，宽按比例
                     towidth = originalImage.Width * height / originalImage.Height;
                     break;
                 case "Cut"://指定高宽裁减（不变形）                
                     if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                     ...{
                         oh = originalImage.Height;
                         ow = originalImage.Height * towidth / toheight;
                         y = 0;
                         x = (originalImage.Width - ow) / 2;
                     }
                     else
                     ...{
                         ow = originalImage.Width;
                         oh = originalImage.Width * height / towidth;
                         x = 0;
                         y = (originalImage.Height - oh) / 2;
                     }
                     break;
                 default:
                     break;
             }

             //新建一个bmp图片
             Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

             //新建一个画板
             Graphics g = System.Drawing.Graphics.FromImage(bitmap);

             //设置高质量插值法
             g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

             //设置高质量,低速度呈现平滑程度
             g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

             //清空画布并以透明背景色填充
             g.Clear(Color.Transparent);

             //在指定位置并且按指定大小绘制原图片的指定部分
             g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                 new Rectangle(x, y, ow, oh),
                 GraphicsUnit.Pixel);

             try
             ...{
                 //以jpg格式保存缩略图
                 return bitmap;
             }
             catch (System.Exception e)
             ...{
                 throw e;
             }
             finally
             ...{
                 originalImage.Dispose();
                 bitmap.Dispose();
                 g.Dispose();
             }
         }
     }
}