net过滤表单和url参数

 void Application_BeginRequest(object sender, EventArgs e)
    {

        //遍历Post参数，隐藏域除外

        if (Regex.IsMatch(Request.RawUrl.ToLower(), @"/manager/") == false)

            for (int i = 0; i < Request.Form.Count; i++)
            {

                if (Request.Form[i].ToString() == "__VIEWSTATE") continue;

                if (IsDanger(Request.Form[i].ToString()))
                {

                    Response.Write("您提交的内容中含有非法字符,已经被拒绝.");

                    Response.End();

                }

            }

        //过滤所有Url中的危险字符串

        if (Request.QueryString.Count > 0 && Regex.IsMatch(Request.RawUrl.ToLower(), @"\.aspx") == true && Regex.IsMatch(Request.RawUrl.ToLower(), @"fckeditor") == false)//如果防止截获fckeditor正常的Url，必须验证".aspx"
        {

            string Temp = "";

            //string Url = Request.Url.AbsoluteUri.Substring(0, Request.Url.AbsoluteUri.LastIndexOf("?"));

            string Url = Request.RawUrl.Substring(0, Request.RawUrl.LastIndexOf("?"));

            for (int i = 0; i < this.Request.QueryString.Count; i++)
            {

                try
                {

                    Temp = HandleRequestParam(this.Request.QueryString[i].ToString());

                    Url += i == 0 ? "?" : "&";

                    Url += Request.QueryString.Keys[i].ToString() + "=" + Temp;

                }

                catch { }

            }

            //if (Url.Length < Request.Url.AbsoluteUri.Length)

               // Response.Redirect(Url);

            Context.RewritePath(Url);//可以用Response.Redirect和Context.RewritePath

        }

        //全站防止页面缓存

        Response.Buffer = true;

        Response.ExpiresAbsolute = DateTime.Now.AddSeconds(-1);

        Response.Expires = 0;

        Response.CacheControl = "no-cache";

    }

    protected string HandleRequestParam(string str)
    {
 
        string RetStr = "";
        char[] strC = str.ToLower().ToCharArray();
        for (int i = 0; i < strC.Length; i++)
        {
            int num = Convert.ToInt32(strC[i]);
            if (num >= 48 && num <= 57)
                RetStr += strC[i].ToString();
            else
                break;
        }

        //string RetStr = str;
        //if (IsDanger(str))
        //{
        //    RetStr = "";
        //}
        return RetStr;
    }

    protected bool IsDanger(string InText)
    {

        string word = @"exec|insert|select|delete|update|master|truncate|char|declare|join|iframe|href|script|<|>|request";

        if (InText == null)

            return false;

        if (Regex.IsMatch(InText, word))

            return true;

        return false;

    }