格式化日期字符串的自定义方法

/// <summary>
    /// 根据系统日期，格式化日期字符串，返回的格式为20100101；
    /// </summary>
    /// <returns>返回格式化号的字符串</returns>
    public static string getday()
    {
        string stryear, strmonth, strday;
        //获取年份的字符串
        stryear = DateTime.Now.Year.ToString();
        //获取当天日期的字符串，格式是“00”
        if (DateTime.Now.Day.ToString().Length != 2)
        {
            strday = "0" + DateTime.Now.Day.ToString();
        }
        else
        {
            strday = DateTime.Now.Day.ToString();
        }
        //获取月份的字符串，格式是“00”月
        if (DateTime.Now.Month.ToString().Length != 2)
        {
            strmonth = "0" + DateTime.Now.Month.ToString();
        }
        else
        {
            strmonth = DateTime.Now.Month.ToString();
        }
        string pcode = stryear + strmonth + strday;
        return pcode;
    }