正在做的项目，关于用电子邮件帐号登录。下面发布一下关于Email格式有效性验证，前后台相结合方式，确保用户所填写是有效信息注册！主要采用正则表达式，比较高效处理事务。

    前台用js对表单进行验证：

   function isEmailTrue(email) {
    var regexpEmail = /\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;
    return regexpEmail.test(email);
    }

  后台采用C#.net验证：

    public  bool CheckEmail(string strEmail)
    {
        int Bz = 1; 
        bool blUserName = false;
        bool blServer = false;  
        bool blDomain = false;  

        char[] charDate = strEmail.Trim().ToCharArray();

        if (strEmail.Trim().Length == 0)
        {
            return false;
        }
        else if (strEmail.Trim().Length > 0 && Char.IsLetterOrDigit(strEmail[0]) == false)
        {
            return false;
        }

        foreach (char c in charDate)
        {
            //验证用户名部分是否输入正确
            if (Bz == 1)
            {
                if (c == '@')
                {
                    Bz = 2;
                    continue;
                }
                if (ValidateUsernamePart(c))
                {
                    if (blUserName == false)
                    {
                        blUserName = true;
                    }
                    continue;
                }
                return false;
            }

            //验证服务器部分是否输入正确
            if (Bz == 2)
            {
                if (c == '.')
                {
                    Bz = 3;
                    continue;
                }

                if (ValidateServerOrDomainPart(c))
                {
                    if (blServer == false)
                    {
                        blServer = true;
                    }
                    continue;
                }
                return false;
            }

            //验证域名部分是否输入正确
            if (Bz == 3)
            {
                if (ValidateServerOrDomainPart(c))
                {
                    if (blDomain == false)
                    {
                        blDomain = true;
                    }
                    continue;
                }
                return false;
            }
        }

        //检查各部分是否有输入为null的.
        if (blUserName == false || blServer == false || blDomain == false)
        {
            return false;
        }

        return true;
    }