/// <summary>
    /// 設定題目
    /// </summary>
    public void SetQuestion()
    {
        answerNumber.sprite = null;
        indexQuestion       = Random.Range(0, paidQuestion.Length);
        PaidQuestion paidQ = paidQuestion[indexQuestion];

        questionNumber1.sprite = questionNumber[paidQ.number1];
        questionSign.sprite    = questionNumber[paidQ.sign == "+" ? 10 : 11];
        questionNumber2.sprite = questionNumber[paidQ.number2];
        questionNumber1.SetNativeSize();
        questionNumber2.SetNativeSize();
        questionSign.SetNativeSize();
    }
    /// <summary>
    /// 點擊按鈕並檢查是否正確
    /// </summary>
    /// <param name="clickNumber">點擊按鈕數字</param>
    private IEnumerator ClickNumberAndCheck(int clickNumber)
    {
        PaidQuestion paidQ  = paidQuestion[indexQuestion];
        int          answer = 0;

        if (paidQ.sign == "+")
        {
            answer = paidQ.number1 + paidQ.number2;
        }
        else
        {
            answer = paidQ.number1 - paidQ.number2;
        }

        answerNumber.sprite = questionNumber[clickNumber];
        answerNumber.SetNativeSize();

        if (clickNumber == answer)
        {
            aud.PlayOneShot(soundCorrect);
            btnClose.interactable = false;
            yield return(new WaitForSeconds(0.5f));

            /* KID 2021.05.10 不顯示付費畫面 - 改顯示設定畫面
             * groupQuestion.alpha = 1;
             * groupQuestion.interactable = true;
             * groupQuestion.blocksRaycasts = true;
             */
            groupPaidPanel.alpha          = 0;
            groupPaidPanel.interactable   = false;
            groupPaidPanel.blocksRaycasts = false;
            groupSettings.alpha           = 1;
            groupSettings.interactable    = true;
            groupSettings.blocksRaycasts  = true;
        }
        else
        {
            aud.PlayOneShot(soundWrong);
            yield return(new WaitForSeconds(0.5f));

            answerNumber.sprite = null;
            SetQuestion();
        }
    }