图片的修改(上传图片时，做的缩小或放大操作）
 
 1         string sFileName = Path.GetFileNameWithoutExtension(this.FileUpload1.FileName);
 2         string sExtension = Path.GetExtension(FileUpload1.FileName);
 3         double size = FileUpload1.PostedFile.ContentLength / 1024;
 4         if (size < 60)
 5         {
 6             string fi = Server.MapPath(@"img/") + sFileName + sExtension;
7             if (sExtension == ".gif" || sExtension == ".jpg" || sExtension == ".bmp" || sExtension == ".png")
 8             {
 9                 System.Drawing.Image image = System.Drawing.Image.FromStream(this.FileUpload1.PostedFile.InputStream);
10                 int width = image.Width;
11                 int height = image.Height;
12                 int max = 40;
13                 try
14                 {
15                     System.Drawing.Image newPic;
16                     if (width > height)
17                     {
18                         newPic = new System.Drawing.Bitmap(image, max, height * max / width);
19                     }
20                     else
21                     {
22                         newPic = new System.Drawing.Bitmap(image, width * max / height, max);
23                     }
24                     newPic.Save(fi, System.Drawing.Imaging.ImageFormat.Jpeg);
25                     img1.Src = @"img\" + sFileName + sExtension;
26                 }
27                 catch (Exception ex)
28                 {
29
30                 }
31             }
32         }