防盗链

/// <summary>
     /// 图片防盗链
     /// </summary>
     public class ImgHandler : IHttpHandler
     {
         const string errImg = "/Content/daolian.jpg";
         public void ProcessRequest(HttpContext context)
         {
             // 获取文件服务器端物理路径
             string FileName = context.Server.MapPath(context.Request.FilePath);
             // 如果UrlReferrer为空，则显示一张默认的禁止盗链的图片
             if (context.Request.UrlReferrer == null || context.Request.UrlReferrer.Host == null)
             {
                 context.Response.ContentType = "image/JPEG";
                 context.Response.WriteFile(errImg);
             }
             else
             {
                 if (context.Request.UrlReferrer.Host.IndexOf("eee114.com") > 0)
                 {
                     context.Response.ContentType = "image/JPEG";
                     context.Response.WriteFile(FileName);
                 }
                 else
                 {
                     context.Response.ContentType = "image/JPEG";
                     context.Response.WriteFile(errImg);
                 }
             }
         }
 
         public bool IsReusable
         {
             get { return true; }
         }
     }

在web.config中的<system.web>节点去调用它

   <!-- HttpHandlers对请求的扩展名进行处理 -->
    <httpHandlers>
      <add path="*.jpg,*.jpeg,*.gif,*.png,*.bmp" verb="*" type="HttpHandler.ImgHandler,HttpHandler" />
    </httpHandlers>