let now = new Date();
            this.nowYear = now.getFullYear();
            this.nowMonth = now.getMonth() + 1; 
            let nowweekday = now.getDate();
            let nowMonths;
            let nowweekdays;
            if (this.nowMonth < 10) {
                nowMonths = "0" + this.nowMonth;
            } else {
                nowMonths = this.nowMonth;
            }
            if (nowweekday < 10) {
                nowweekdays = "0" + nowweekday;
            } else {
                nowweekdays = nowweekday;
            }

             let hh = now.getHours();            //时
             let mm = now.getMinutes();          //分
             let ss = now.getSeconds();           //秒
             let hhs, mms, sss;
             if (hh < 10) {
                hhs = "0" + hh;
             } else {
                  hhs = hh;
              }
              if (mm < 10) {
                 mms = "0" + mm;
             } else {
                  mms = mm;
              }
              if (ss < 10) {
                  sss = "0" + ss;
             } else {
                  sss = ss;
              }
            this.XXlabel.text = this.nowYear + "-" + nowMonths + "-" + nowweekdays + "  " + hhs + ":" + mms + ":" + sss;

　　若是做时间控件的话，考虑到时间格式统一，可以单独设置一个函数，将传入的时间数字同“10”进行比较，若小于则前加“0”；反之不做处理