采用Global.asax的Application_BeginRequest事件过滤敏感字符

1、特殊字符过滤公共类ProcessRequest.cs

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

namespace COMP
{
public class ProcessRequest
{
     public void StartProcessRequest()
        {
            try
            {
                string getkeys = "";
                string sqlErrorPage = "/";
                if (System.Web.HttpContext.Current.Request.QueryString != null)
                {   

                    for (int i = 0; i < System.Web.HttpContext.Current.Request.QueryString.Count; i++)
                    {
                        getkeys = System.Web.HttpContext.Current.Request.QueryString.Keys[i];
                        if (!ProcessSqlStr(System.Web.HttpContext.Current.Request.QueryString[getkeys].ToLower()))
                        {
                            System.Web.HttpContext.Current.Response.Redirect(sqlErrorPage);
                            System.Web.HttpContext.Current.Response.End();
                        }
                    }
                }   

            }
            catch
            {   

            }
        }
        /**/
        /// <summary>
        /// 分析用户请求是否正常
        /// </summary>
        /// <param name="Str">传入用户提交数据</param>
        /// <returns>返回是否含有SQL注入式攻击代码</returns>
        private bool ProcessSqlStr(string Str)
        {
            bool ReturnValue = true;
            try
            {
                if (Str != "" && Str != null)
                {
                    string SqlStr = "";
                    if (SqlStr == "" || SqlStr == null)
                    {
                        SqlStr = "'|and|exec|insert|select|delete|update|count|*|chr|mid|master|truncate|char|declare";
                    }
                    string[] anySqlStr = SqlStr.Split('|');
                    foreach (string ss in anySqlStr)
                    {
                        if (Str.IndexOf(ss) >= 0)
                        {
                            ReturnValue = false;
                        }
                    }
                }
            }
            catch
            {
                ReturnValue = false;
            }
            return ReturnValue;
        }   

    }
}  

2、Global.asax的Application_BeginRequest事件

 void Application_BeginRequest(object source, EventArgs e)
    {

        COMP.ProcessRequest pr = new COMP.ProcessRequest();
        pr.StartProcessRequest();
    }