CocosCreator中，以时分秒的形式显示秒数

时分秒的形式：如“12:02:25”。

    private formatTime(totalSeconds: number): string
    { 
        let hours: number = this.rounding((totalSeconds / 3600));
        let hh: string = (hours < 10 ? "0" + hours : hours).toString();
        let minutes: number = this.rounding((totalSeconds - hours * 3600) / 60);
        let mm: string = minutes < 10 ? "0" + minutes : minutes.toString();
        let seconds: number = this.rounding(totalSeconds - hours * 3600 - minutes * 60);
        let ss: string = seconds < 10 ? "0" + seconds : seconds.toString();
        let num: string = hh + ":" + mm + ":" + ss;
        return num;
    }
    private rounding(num: number): number
    { 
        return Math.floor(num);
    }