/// <summary>

         /// 会产生graphics异常的PixelFormat

         /// </summary>

         private static PixelFormat[] indexedPixelFormats = { PixelFormat.Undefined, PixelFormat.DontCare,

 PixelFormat.Format16bppArgb1555, PixelFormat.Format1bppIndexed, PixelFormat.Format4bppIndexed,

 PixelFormat.Format8bppIndexed

     };

         /// <summary>

         /// 判断图片的PixelFormat 是否在 引发异常的 PixelFormat 之中

         /// </summary>

         /// <param name="imgPixelFormat">原图片的PixelFormat</param>

         /// <returns></returns>

         private static bool IsPixelFormatIndexed(PixelFormat imgPixelFormat)

         {

             foreach (PixelFormat pf in indexedPixelFormats)

             {

                 if (pf.Equals(imgPixelFormat)) return true;

             }

             return false;

         }

        /// <summary>

         /// 在图片上生成图片水印

         /// </summary>

         /// <param name="Path">原服务器图片路径</param>

         /// <param name="Path_syp">生成的带图片水印的图片路径</param>

         /// <param name="Path_sypf">水印图片路径</param>

         public static void AddShuiYinPic(string Path, string Path_syp, string Path_sypf)

         {

             System.Drawing.Image image = System.Drawing.Image.FromFile(Path);

             System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf);

             System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);

             g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), , , copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel);

             g.Dispose();

             image.Save(Path_syp);

             image.Dispose();

         }

         /// <summary>

         /// 在图片上增加文字水印

         /// </summary>

         /// <param name="Path">原服务器图片路径</param>

         /// <param name="Path_sy">生成的带文字水印的图片路径</param>

         public static void AddShuiYinWord(string Path, string Path_sy)

         {

             using (System.Drawing.Image img = System.Drawing.Image.FromFile(Path))

             {

                 //如果原图片是索引像素格式之列的，则需要转换

                 if (IsPixelFormatIndexed(img.PixelFormat))

                 {

                     Bitmap bmp = new Bitmap(img.Width, img.Height, PixelFormat.Format32bppArgb);

                     using (Graphics g = Graphics.FromImage(bmp))

                     {

                         g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

                         g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

                         g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;

                         g.DrawImage(img, , );

                         System.Drawing.Font f = new System.Drawing.Font("Verdana", );

                         System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Red);

                         g.DrawString("爱智旮旯", f, b, , );

                     }

                     bmp.Save(Path_sy);

                     bmp.Dispose();

                 }

                 else //否则直接操作

                 {

                     string addText = "爱智旮旯";

                     System.Drawing.Image image = System.Drawing.Image.FromFile(Path);

                     System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);

                     g.DrawImage(image, , , image.Width, image.Height);

                     System.Drawing.Font f = new System.Drawing.Font("Verdana", );

                     System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Blue);

                     g.DrawString(addText, f, b, , );

                     g.Dispose();

                     image.Save(Path_sy);

                     image.Dispose();

                 }

             } 

         }

         /// <summary>

         /// 生成缩略图

         /// </summary>

         /// <param name="originalImagePath">源图路径（物理路径）</param>

         /// <param name="thumbnailPath">缩略图路径（物理路径）</param>

         /// <param name="width">缩略图宽度</param>

         /// <param name="height">缩略图高度</param>

         /// <param name="mode">生成缩略图的方式</param>

         public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)

         {

             System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

             int towidth = width;

             int toheight = height;

             int x = ;

             int y = ;

             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 = ;

                         x = (originalImage.Width - ow) / ;

                     }

                     else

                     {

                         ow = originalImage.Width;

                         oh = originalImage.Width * height / towidth;

                         x = ;

                         y = (originalImage.Height - oh) / ;

                     }

                     break;

                 default:

                     break;

             }

             //新建一个bmp图片

             System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

             //新建一个画板

             System.Drawing.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(System.Drawing.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 System.Drawing.Rectangle(, , towidth, toheight),

             new System.Drawing.Rectangle(x, y, ow, oh),

             System.Drawing.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();

             }

         }

       protected void Button1_Click(object sender, EventArgs e)

         {

             if (FileUpload1.HasFile)

             {

                 string fileContentType = FileUpload1.PostedFile.ContentType;

                 if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg" || fileContentType == "image/jpg")

                 {

                     string name = FileUpload1.PostedFile.FileName; // 客户端文件路径

                     FileInfo file = new FileInfo(name);

                     string fileName = file.Name; // 文件名称

                     string fileName_s = "s_" + file.Name; // 缩略图文件名称

                     string fileName_sy = "sy_" + file.Name; // 水印图文件名称（文字）

                     string fileName_syp = "syp_" + file.Name; // 水印图文件名称（图片）

                     //以下路径可以根据情况进行修改

                     string webFilePath = Server.MapPath("file/" + fileName); // 服务器端文件路径

                     string webFilePath_s = Server.MapPath("file/" + fileName_s);　　// 服务器端缩略图路径

                     string webFilePath_sy = Server.MapPath("file/" + fileName_sy);　// 服务器端带水印图路径(文字)

                     string webFilePath_syp = Server.MapPath("file/" + fileName_syp);　// 服务器端带水印图路径(图片)

                     //以下为水印图片的路径一定要先准备一张水印图片！

                     string webFilePath_sypf = Server.MapPath("file/shuiyin.jpg");　// 服务器端水印图路径(图片)

                     if (!File.Exists(webFilePath))

                     {

                         try

                         {

                             FileUpload1.SaveAs(webFilePath); // 使用 SaveAs 方法保存文件

                             AddShuiYinWord(webFilePath, webFilePath_sy);

                             //AddShuiYinPic(webFilePath, webFilePath_syp, webFilePath_sypf);

                             MakeThumbnail(webFilePath, webFilePath_s, , , "Cut"); // 生成缩略图方法

                             Label1.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + FileUpload1.PostedFile.ContentType + "，文件大小为：" + FileUpload1.PostedFile.ContentLength + "B";

                         }

                         catch (Exception ex)

                         {

                             Label1.Text = "提示：文件上传失败，失败原因：" + ex.Message;

                         }

                     }

                     else

                     {

                         Label1.Text = "提示：文件已经存在，请重命名后上传";

                     }

                 }

                 else

                 {

                     Label1.Text = "提示：文件类型不符";

                 }

             }

         }