在Global.asax文件中

protected void Application_BeginRequest(Object sender, EventArgs e)
        {
            //SQL防注入
            string Sql_1 = "exec|insert+|select+|delete|update|count|chr|mid|master+|truncate|char|declare|drop+|drop+table|creat+|creat+table";
            string Sql_2 = "exec+|insert+|delete+|update+|count(|count+|chr+|+mid(|+mid+|+master+|truncate+|char+|+char(|declare+|drop+|creat+|drop+table|creat+table";
            string[] sql_c = Sql_1.Split('|');
            string[] sql_c1 = Sql_2.Split('|');
　　
            if(Request.QueryString != null)
            {
                foreach (string sl in sql_c)
                {
                    if(Request.QueryString.ToString().ToLower().IndexOf(sl.Trim()) >=0)
                    {
                        Response.Write("警告！你的IP已经被记录!");//吓唬人的
                        Response.Write(sl);
                        Response.Write(Request.QueryString.ToString());
                        //System.Windows.Forms.MessageBox.Show("禁止提交外部数据","1",System.Windows.F
                        //orms.MessageBoxButtons.OK,System.Windows.Forms.MessageBoxIcon.Error,System.Windows.Forms.MessageBoxDefaultButton.Button1,System.Windows.Forms.MessageBoxOptions.DefaultDesktopOnly);
                        //Response.Redirect("http://www.163.com");
                        Response.End();
                        break;
                    }
                }
            }
   
            if(Request.Form.Count > 0)
            {
    
                string s1 = Request.ServerVariables["SERVER_NAME"].Trim();//服务器名称
                if(Request.ServerVariables["HTTP_REFERER"] != null)
                {
                    string s2 = Request.ServerVariables["HTTP_REFERER"].Trim();//http接收的名称
                    string s3 = "";
                    if(s1.Length > (s2.Length -7))
                    {
                        s3 = s2.Substring(7);
                    }
                    else
                    {
                        s3 = s2.Substring(7,s1.Length);
                    }
                    if(s3 != s1)
                    {
                        Response.Write("你的IP已被记录！警告！");//吓人的
                        //System.Windows.Forms.MessageBox.Show("禁止提交外部数据","1",System.Windows.Forms.MessageBoxButtons.OK,Sy
                        //stem.Windows.Forms.MessageBoxIcon.Error,System.Windows.Forms.MessageBoxDefaultButton.Button1,System.Windows.Forms.MessageBoxOptions.DefaultDesktopOnly);
                        //Response.Redirect("http://www.163.com");
                        Response.End();
                    }
                } 
            }
        }