aspx 中防止sql注入

public class SqlInject:Page
    {
        //检测到注入后的处理方式: 0:仅警告；1：警告+记录；2：警告+自定义错误页面；3：警告+记录+自定义错误页面  
        private const int _type = 0;
        private const string errRedirectPage = "/err.aspx";
        //如果记录注入信息，那么请设置：errMDBpath：数据库路径  
        private const string errMDBpath = "/SqlInject.mdb";
        //过滤特征字符  
        //过滤特征字符  
        private static string StrKeyWord = ConfigurationManager.AppSettings["SqlKeyWord"]; //@"select|insert|delete|from|count(|drop table|update|truncate|asc(|mid(|char(|xp_cmdshell|exec|master|net local group administrators|net user|or|and";  
        private static string StrRegex = ConfigurationManager.AppSettings["SqlRegex"];  //@";|/|(|)|[|]|{|}|%|@|*|‘|!"; // 原始过滤条件：【-|;|,|/|(|)|[|]|{|}|%|@|*|‘|!】  
        private HttpRequest request;
        public SqlInject(System.Web.HttpRequest _request)
        {
            this.request = _request;
        }
        ///<summary>  
        ///检测SQL注入及记录、显示出错信息  
        ///</summary>  
        public void CheckSqlInject()
        {
            bool isInject = false;
            if (CheckRequestQuery() || CheckRequestForm())
            {
                isInject = true;
            }
            else
            {
                return;
            }

            switch (_type)
            {
                case 0:
                    ShowErr();
                    break;
                case 1:
                    ShowErr();
                    SaveToMdb();
                    break;
                case 2:
                    ShowErr();
                    string temp;
                    System.Web.HttpContext.Current.Response.Write("<script>setTimeout(\"" + "location.href=‘" + errRedirectPage + "‘" + "\",5000)</script>");
                    break;
                case 3:
                    ShowErr();
                    SaveToMdb();
                    System.Web.HttpContext.Current.Response.Write("<script>setTimeout(\"" + "location.href=‘" + errRedirectPage + "‘" + "\",5000)</script>");
                    break;
                default:
                    break;
            }
            System.Web.HttpContext.Current.Response.End();

        }
        private void SaveToMdb()
        {
            OleDbConnection conn = new OleDbConnection("Provider=Microsoft.JET.OLEDB.4.0;Data Source=" + Server.MapPath(errMDBpath));
            conn.Open();
            OleDbCommand cmd = conn.CreateCommand();

            cmd.CommandText = "insert into [Record] (sIP,sDate,sPath) values (‘" +
                 request.ServerVariables["REMOTE_ADDR"].ToString() + "‘,‘" +
                 DateTime.Now + "‘,‘" + request.ServerVariables["URL"].ToLower() + RelaceSingleQuotes(request.QueryString.ToString()) + "‘)";
            int code = cmd.ExecuteNonQuery();
            if (code == 1)
                HttpContext.Current.Response.Write("<br>****以上信息已记录至日志数据库****");
            else
                HttpContext.Current.Response.Write("<br>日志数据库出错");
            conn.Close();

        }

        private string RelaceSingleQuotes(string _url)
        {
            string URL = _url.Replace("‘", "单引号");
            return URL;
        }
        private void ShowErr()
        {
            //string msg = @"<font color=red>请不要尝试未授权之入侵检测！</font>" + @"<br><br>";  
            //msg += @"操作IP：" + request.ServerVariables["REMOTE_ADDR"] + @"<br>";  
            //msg += @"操作时间：" + DateTime.Now + @"<br>";  
            //msg += @"页面：" + request.ServerVariables["URL"].ToLower() + request.QueryString.ToString() + @"<br>";  
            //msg += @"<a href=‘#‘ onclick=‘javascript:window.close()‘>关闭</a>";  
            //System.Web.HttpContext.Current.Response.Clear();  
            //System.Web.HttpContext.Current.Response.Write(msg);  
            HttpContext.Current.Response.Write("<script>alert(‘请不要尝试未授权之入侵检测！‘);javascript:history.go(-1);</script>");
        }
        ///<summary>  
        /// 特征字符  
        ///</summary>  
        public static string KeyWord
        {
            get
            {
                return StrKeyWord;
            }
        }
        ///<summary>  
        /// 特征符号  
        ///</summary>  
        public static string RegexString
        {
            get
            {
                return StrRegex;
            }
        }

        ///<summary>  
        ///检查字符串中是否包含Sql注入关键字  
        /// <param name="_key">被检查的字符串</param>  
        /// <returns>如果包含注入true;否则返回false</returns>  
        ///</summary>  
        private static bool CheckKeyWord(string _key)
        {
            string[] pattenString = StrKeyWord.Split(‘|‘);
            string[] pattenRegex = StrRegex.Split(‘|‘);
            foreach (string sqlParam in pattenString)
            {
                if (_key.Contains(sqlParam + " ") || _key.Contains(" " + sqlParam))
                {
                    return true;
                }
            }
            foreach (string sqlParam in pattenRegex)
            {
                if (_key.Contains(sqlParam))
                {
                    return true;
                }
            }
            return false;

        }
        ///<summary>  
        ///检查URL中是否包含Sql注入  
        /// <param name="_request">当前HttpRequest对象</param>  
        /// <returns>如果包含注入true;否则返回false</returns>  
        ///</summary>  
        public bool CheckRequestQuery()
        {
            if (request.QueryString.Count > 0)
            {
                foreach (string sqlParam in this.request.QueryString)
                {
                    if (sqlParam == "__VIEWSTATE") continue;
                    if (sqlParam == "__EVENTVALIDATION") continue;
                    if (CheckKeyWord(request.QueryString[sqlParam].ToLower()))
                    {
                        return true;
                    }
                }
            }
            return false;
        }
        ///<summary>  
        ///检查提交的表单中是否包含Sql注入  
        /// <param name="_request">当前HttpRequest对象</param>  
        /// <returns>如果包含注入true;否则返回false</returns>  
        ///</summary>  
        public bool CheckRequestForm()
        {
            if (request.Form.Count > 0)
            {
                foreach (string sqlParam in this.request.Form)
                {
                    if (sqlParam == "__VIEWSTATE") continue;
                    if (sqlParam == "__EVENTVALIDATION") continue;
                    if (CheckKeyWord(request.Form[sqlParam]))
                    {
                        return true;
                    }
                }
            }
            return false;
        }  
    }
}