我的 if 语句没有执行，我该如何解决这个问题？答案

【问题标题】：My if statement is not executing, how can I solve this?我的 if 语句没有执行，我该如何解决这个问题？
【发布时间】：2015-02-24 08:37:36
【问题描述】：

我正在用 JavaFX 制作 BlackJack 游戏。到目前为止，一切都很顺利。唯一缺少的是游戏应该停止并且玩家应该在牌的总价值超过 21 时出局，就像真正的游戏一样。我在我的代码中添加了一个 if 语句。好消息是，if 语句执行。坏消息是，它在总值超过 21 之后执行。所以当值是 23 时玩家仍然可以击中。然后 if 语句将不会执行。它在玩家再次击球时执行，例如 23 变为 25。

我希望我解释得很好，否则请给我反馈。

这是我的代码：

    public class FXMLDocumentController implements Initializable {

    private int playerValue, dealerValue, playerTotal, dealerTotal;





    Random ran = new Random();
    @FXML
    private TextArea dealerArea;
    @FXML
    private TextArea playerArea;
    @FXML
    private Label labelPlayerTotal;
    @FXML
    private Label labelDealerTotal;
    @FXML
    private Label labelWinner;
    @FXML
    private Button hitButton;
    @FXML
    private Button stayButton;
    @FXML
    private Button replayButton;





    public void drawCardForPlayer(ActionEvent event) {

        stayButton.setDisable(false);
        playerValue = ran.nextInt(14);

        while (playerValue <=1) {
            playerValue = ran.nextInt(14);
        }
        ######################################
        // I created this broken if statement
        if (playerTotal >21) {

            labelWinner.setText("You busted, dealer won!");
            hitButton.setDisable(true);
            stayButton.setDisable(true);

        }
        #########################
        switch (playerValue) {

        case 2:
            playerArea.appendText("\t" + Deck.drawTwo());
            playerTotal = 2 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 3:
            playerArea.appendText("\t" + Deck.drawThree()); 
            playerTotal = 3 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 4:
            playerArea.appendText("\t" + Deck.drawFour()); 
            playerTotal = 4 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 5:
            playerArea.appendText("\t" + Deck.drawFive()); 
            playerTotal = 5 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 6:
            playerArea.appendText("\t" + Deck.drawSix()); 
            playerTotal = 6 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 7:
            playerArea.appendText("\t" + Deck.drawSeven());
            playerTotal = 7 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 8:
            playerArea.appendText("\t" + Deck.drawEight()); 
            playerTotal = 8 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 9:
            playerArea.appendText("\t" + Deck.drawNine());
            playerTotal = 9 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

        case 11:
            playerArea.appendText("\t" + Deck.drawJack());
            playerTotal = 10 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;
        case 12:
            playerArea.appendText("\t" + Deck.drawQueen()); 
            playerTotal = 10 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;
        case 13:
            playerArea.appendText("\t" + Deck.drawKing());
            playerTotal = 10 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;
        case 14:
            playerArea.appendText("\t" + Deck.drawAce());
            playerTotal = 11 + playerTotal;
            labelPlayerTotal.setText("Playertotal:" + playerTotal);
            break;

            default:
            break;

        }



    }
   }
   }

我调试了一下，发现playerTotal的值一开始是0，而playerTotal的值只是在switch-case中初始化的，这就是问题所在。我该如何解决这个问题？

【问题讨论】：

标签： java xml user-interface javafx logic

【解决方案1】：

playerTotal 直到您的switch 才会更新。让您的 if 语句检查 PlayerTotal + playerValue > 21

【讨论】：

是的，我现在修好了。感谢您的帮助。
@Smile 如果这回答了您的问题，您应该将答案标记为正确。

【解决方案2】：

您应该将 if 条件移到获取新随机卡的代码之前。

    if (playerTotal >21) {

        labelWinner.setText("You busted, dealer won!");
        hitButton.setDisable(true);
        stayButton.setDisable(true);

    }

    stayButton.setDisable(false);
    playerValue = ran.nextInt(14);

    while (playerValue <=1) {
        playerValue = ran.nextInt(14);
    }
    switch (playerValue) {
        ....

【讨论】：

我试过了，playerTotal的值最初还是0。
@Smile 它最初应该是 0（在添加任何卡片之前）。重要的是，在获得新卡之前，您要测试当前总数不超过 21。