asp.net 经常用到需要判断文本框是否输入的数字是小数，有无正负，几位小数，可以封装一起判断

    /// <summary>
    /// 判断是否为小数点数字且带符号
    /// </summary>
    /// <param name="symbol">A:正负,P:正数</param>
    /// <param name="message">小数点位数</param>
    /// <param name="message">需检查的数字参数</param>
    /// <returns>返回值</returns>
    public static bool CheckIsNumberic(string type, string message,int intLength)
    {
        System.Text.RegularExpressions.Regex rex;
        //(@"^\-?\d+(\.\d{1,2})?$")   正负
        //(@"^\d+(\.\d{1,2})?$")  正数

        switch (type)    //A  正负数  P 正数 positive N 负数 negative
        {
            case "A":
                rex = new System.Text.RegularExpressions.Regex(@"^\-?\d+(\.\d{1," + intLength + "})?$");
                break;
            case "P":
                rex = new System.Text.RegularExpressions.Regex(@"^\d+(\.\d{1," + intLength + "})?$");
                break;
            default:
                rex = new System.Text.RegularExpressions.Regex(@"^\-?\d+(\.\d{1," + intLength + "})?$");
                break;
        }
        if (rex.IsMatch(message))
        {
            return true;
        }
        else
            return false;
    }

//调用，比如不能超过2位小数
     CheckIsNumberic("P", txtUnitPrice.Text.Trim(), 2)