public string Timer()
    {
        ts = new TimeSpan(0, 0, (int)time);
        str = "";
        if (ts.Hours > 0)
        {
            str = ts.Hours.ToString() + "小时 " + ts.Minutes.ToString() + "分钟 " + ts.Seconds + "秒";
        }
        if (ts.Hours == 0 && ts.Minutes > 0)
        {
            str = ts.Minutes.ToString() + "分钟 " + ts.Seconds + "秒";
        }
        if (ts.Hours == 0 && ts.Minutes == 0)
        {
            str = ts.Seconds + "秒";
        }
        return str;
    }