图片盗链 获得 访问者ip地址

 public void ProcessRequest(HttpContext context)
        {
            //context.Response.ContentType = "text/html";//返回一个text的东西，也就是string
            context.Response.ContentType = "image/JPEG";
            string fullpath = HttpContext.Current.Server.MapPath("Hydrangeas.JPG");
             using(System.Drawing.Bitmap bitmap  = new System.Drawing.Bitmap(fullpath))
             {
                 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap))
                 {
                     if (context.Request.UrlReferrer == null)//直接访问图片，就是UrlReferrer == null
                     {
                         g.Clear(System.Drawing.Color.White);
                         g.DrawString("禁止直接访问图片，请在页面中查看图片",new System.Drawing.Font("宋体",30),System.Drawing.Brushes.Red,0,0);
                     }
                     else if (context.Request.UrlReferrer.Host != "localhost")//如果访问图片的网址不是localhost，localhost可以变成具体网址
                     {
                         g.Clear(System.Drawing.Color.White);
                         g.DrawString("不要盗链", new System.Drawing.Font("宋体", 30), System.Drawing.Brushes.Red, 0, 0);
                     }

                 }

 g.DrawString("你的ip地址是:"+context.Request.UserHostAddress, new System.Drawing.Font("宋体", 30), System.Drawing.Brushes.Red, 0, 0);//获得访问者的ip地址

                 bitmap.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
             }
           
        }