【IHttpHandler】使用IHttpHandler防盗链

防盗链的原理，从图片请求的URL地址上判断是否是我们自己网站上的域名，如果不是，恭喜，你的图片已经被盗链了！

那么我来介绍下图片放盗链的一个方法

首先，添加个httpHandlers请求，webconfig部分配置节如下：

<httpHandlers>
          <add verb="*" path="*.jpg" type="myhandler,App_Code"/>
    </httpHandlers>

然后添加个class,取名为myhandler继承于IHttpHandler

隐藏行号 复制代码 ？ 防盗链

1. using System;
   

2. using System.Data;
   

3. using System.Configuration;
   

4. using System.Web;
   

5. using System.Web.Security;
   

6. using System.Web.UI;
   

7. using System.Web.UI.WebControls;
   

8. using System.Web.UI.WebControls.WebParts;
   

9. using System.Web.UI.HtmlControls;
   

10. public class myhandler : IHttpHandler
    

11. {
    

12.     public void ProcessRequest(HttpContext context)
    

13.     {
    

14.         string FileName = context.Server.MapPath(context.Request.FilePath);
    

15.         if (context.Request.UrlReferrer.Host == null)
    

16.         {
    

17.             context.Response.ContentType = "image/JPEG";
    

18.             context.Response.WriteFile("~/images/no.png");//被替换图片
    

19.         }
    

20.         else
    

21.         {
    

22.             if (context.Request.UrlReferrer.Host.IndexOf("localhost") > -1)//这里是你的域名
    

23.             {
    

24.                 context.Response.ContentType = "image/JPEG";
    

25.                 context.Response.WriteFile(FileName);
    

26.             }
    

27.             else
    

28.             {
    

29.                 context.Response.ContentType = "image/JPEG";
    

30.                 context.Response.WriteFile("~/images/no.png");
    

31.             }
    

32.         }
    

33.     }
    

35.     public bool IsReusable
    

36.     {
    

37.         get { return true; }
    

38.     }
    

40.     public myhandler()
    

41.     {
    

43.     }
    

44. }
    

.src_container{background-color:#e7e5dc; width:99%; overflow:hidden; margin:12px 0 12px 0 !important; padding:0px 3px 3px 0px}
.src_container .titlebar{ background-color:#d4dfff; border:1px solid #4f81bd; border-bottom:0; padding:3px 24px; margin:0; width:auto; line-height:120%; overflow:hidden; text-align:left; font-size:12px}
.src_container .toolbar{ display:inline; font-weight:normal; font-size:100%; float:right; cursor:hand; color:#00f; text-align:left; overflow:hidden}
.toolbar span.button{ display:inline; font-weight:normal; font-size:100%; cursor:hand; color:#00f; text-align:left; overflow:hidden; cursor:pointer;}
.src_container div.clientarea{ background-color:white; border:1px solid #4f81bd; margin:0; width:auto !important; width:100%; height:auto; overflow:auto; text-align:left; font-size:12px; font-family: "Courier New","Consolas","Fixedsys",courier,monospace,serif}
.src_container ol.mainarea{ padding:0 0 0 52px; margin:0; background-color:#f7f7ff !important}
.number_show{ padding-left:52px !important; list-style:decimal outside !important}
.number_show li{ list-style:decimal outside !important; border-left:1px dotted #4f81bd}
.number_hide{ padding-left:0px !important; list-style-type:none !important}
.number_hide li{ list-style-type:none !important; border-left:0px}
ol.mainarea li{ display:list-item !important; font-size:12px !important; margin:0 !important; line-height:18px !important; padding:0 0 0 0px !important; background-color:#f7f7ff !important; color:#4f81bd}
ol.mainarea li pre{color:black; line-height:18px; padding:0 0 0 12px !important; margin:0em; background-color:#fff !important}
.linewrap ol.mainarea li pre{white-space:pre-wrap; white-space:-moz-pre-wrapwhite-space:-pre-wrap; white-space:-o-pre-wrap; word-wrap:break-word}
ol.mainarea li pre.alt{ background-color:#f7f7ff !important}

myhandler继承自IHttpHandler实现了对url来源来判断jpg图片是否被盗链，本class中以localhost为例，修改localhost和images/no.png参数即可.