void Start()
    {
        SaveModel save = SaveModel.GetInstance();

        interval = new Vector3(0, -1.4f, 0);
        Grade currentGrade = save.GetCurrentGrade();

        currentCorrectCount.text = currentGrade.CorrectCount.ToString();
        currentUsingTime.text    = currentGrade.UsingTime.ToString();
        SaveModel.GetInstance().SortGrade();
        Vector3 initPosition = gradeOriginObject.transform.position;
        int     count        = save.AllGrades.Count > 5 ? 5 : save.AllGrades.Count; //排行榜上成绩最多5个

        for (int i = 0; i < count; ++i)                                             //循环显示所有成绩
        {
            GameObject gradeObject = Instantiate(gradeOriginObject, initPosition + i * interval, Quaternion.identity);
            gradeObject.transform.parent = GameObject.Find("leaderboard").transform;
            SetGrade(gradeObject.transform, save.AllGrades[i], i + 1);
        }
    }