ASP.NET防盗链技术

<%@ WebHandler Language="C#" Class="Handler" %>
using System;
using System.Web;
public class Handler : IHttpHandler {
   
    public void ProcessRequest (HttpContext context) {
        if (context.Request.UrlReferrer.Host == "10.11.43.52")
        {
            context.Response.Expires = 0;
            context.Response.Clear();
            context.Response.ContentType = "image/jpg";
            context.Response.WriteFile(context.Request.PhysicalPath);
            context.Response.End();
        }
        else
        {
            context.Response.Expires = 0;
            context.Response.Clear();
            context.Response.ContentType = "image/jpg";
            context.Response.WriteFile(context.Request.PhysicalApplicationPath+"error.jpg");
            context.Response.End();
        }
    }
 
    public bool IsReusable {
        get {
            return true;
        }
    }
}
1、一般处理程序文件（VS2008下可以直接编译通过），如果是VS2005，则须写入App_code然后进行编译
using Syste