图片操作，图片上放个水印图片

 1 <%@ WebHandler Language="C#" Class="ShuiYin" %>
 2 
 3 using System;
 4 using System.Web;
 5 using System.Drawing;
 6 
 7 public class ShuiYin : IHttpHandler {
 8     
 9     public void ProcessRequest (HttpContext context) {
10         context.Response.ContentType = "text/jpeg";
11         //context.Response.Write("Hello World");
12         //读取原图
13         using (Image img=System.Drawing.Image.FromFile(context.Server.MapPath("download/1.jpg")))
14         {
15             //读取水印图片
16             using (Image imgWater=Image.FromFile(context.Server.MapPath("download/2.jpg")))
17             {
18                 //创建一个“画布”
19                 using (Graphics g=Graphics.FromImage(img))
20                 {
21                     //把水印图片画到“原图”上
22                     g.DrawImage(imgWater,new Rectangle(100,100,imgWater.Width,img.Height),new Rectangle(0,0,imgWater.Width,imgWater.Height),GraphicsUnit.Pixel);
23                 }
24                 img.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
25             }
26         }
27     }
28  
29     public bool IsReusable {
30         get {
31             return false;
32         }
33     }
34 
35 }