用Java实现图形化界面的21点游戏

以下是一个简单的21点游戏的Java图形化界面实现，你可以在此基础上进行扩展和优化。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Collections;

public class TwentyOneGame extends JFrame implements ActionListener {
    private final int WIDTH = 800;
    private final int HEIGHT = 600;
    private final int CARD_WIDTH = 71;
    private final int CARD_HEIGHT = 96;

    private JLabel playerLabel;
    private JLabel dealerLabel;
    private JLabel resultLabel;
    private JButton hitButton;
    private JButton standButton;
    private JButton newGameButton;

    private ArrayList<Card> deck;
    private ArrayList<Card> playerHand;
    private ArrayList<Card> dealerHand;

    private int playerScore;
    private int dealerScore;

    public TwentyOneGame() {
        setTitle("Twenty-One Game");
        setSize(WIDTH, HEIGHT);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        add(panel);

        playerLabel = new JLabel("Player's Hand");
        dealerLabel = new JLabel("Dealer's Hand");
        resultLabel = new JLabel("");
        hitButton = new JButton("Hit");
        standButton = new JButton("Stand");
        newGameButton = new JButton("New Game");

        hitButton.addActionListener(this);
        standButton.addActionListener(this);
        newGameButton.addActionListener(this);

        panel.add(playerLabel);
        panel.add(Box.createRigidArea(new Dimension(0, 10)));
        panel.add(dealerLabel);
        panel.add(Box.createRigidArea(new Dimension(0, 10)));
        panel.add(hitButton);
        panel.add(Box.createRigidArea(new Dimension(0, 10)));
        panel.add(standButton);
        panel.add(Box.createRigidArea(new Dimension(0, 10)));
        panel.add(newGameButton);
        panel.add(Box.createRigidArea(new Dimension(0, 10)));
        panel.add(resultLabel);

        newGame();
    }

    private void newGame() {
        deck = new ArrayList<>();
        for (Suit suit : Suit.values()) {
            for (Rank rank : Rank.values()) {
                deck.add(new Card(rank, suit));
            }
        }
        Collections.shuffle(deck);

        playerHand = new ArrayList<>();
        dealerHand = new ArrayList<>();

        playerHand.add(dealCard());
        playerHand.add(dealCard());

        dealerHand.add(dealCard());
        dealerHand.add(dealCard());

        playerScore = calculateScore(playerHand);
        dealerScore = calculateScore(dealerHand);

        updatePlayerLabel();
        updateDealerLabel();
        updateResultLabel();

        hitButton.setEnabled(true);
        standButton.setEnabled(true);
    }

    private Card dealCard() {
        return deck.remove(0);
    }

    private int calculateScore(ArrayList<Card> hand) {
        int score = 0;
        for (Card card : hand) {
            if (card.getRank().getValue() == 1) {
                if (score + 11 <= 21) {
                    score += 11;
                } else {
                    score += 1;
                }
            } else {
                score += Math.min(card.getRank().getValue(), 10);
            }
        }
        return score;
    }

    private void updatePlayerLabel() {
        playerLabel.setText("Player's Hand (" + playerScore + "):");
        JPanel playerPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        for (Card card : playerHand) {
            playerPanel.add(new JLabel(new ImageIcon(card.getImage().getScaledInstance(CARD_WIDTH, CARD_HEIGHT, Image.SCALE_SMOOTH))));
        }
        playerLabel.setLabelFor(playerPanel);
        playerLabel.add(playerPanel);
    }

    private void updateDealerLabel() {
        dealerLabel.setText("Dealer's Hand (" + dealerHand.get(0).getRank().getValue() + "):");
        JPanel dealerPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        dealerPanel.add(new JLabel(new ImageIcon(dealerHand.get(0).getImage().getScaledInstance(CARD_WIDTH, CARD_HEIGHT, Image.SCALE_SMOOTH))));
        if (dealerHand.size() == 2) {
            dealerPanel.add(new JLabel(new ImageIcon(Card.getBackImage().getScaledInstance(CARD_WIDTH, CARD_HEIGHT, Image.SCALE_SMOOTH))));
        }
        dealerLabel.setLabelFor(dealerPanel);
        dealerLabel.add(dealerPanel);
    }

    private void updateResultLabel() {
        if (playerScore > 21) {
            resultLabel.setText("Player busts! Dealer wins!");
            hitButton.setEnabled(false);
            standButton.setEnabled(false);
        } else if (dealerScore > 21) {
            resultLabel.setText("Dealer busts! Player wins!");
            hitButton.setEnabled(false);
            standButton.setEnabled(false);
        } else if (!hitButton.isEnabled()) {
            if (playerScore > dealerScore) {
                resultLabel.setText("Player wins!");
            } else if (playerScore < dealerScore) {
                resultLabel.setText("Dealer wins!");
            } else {
                resultLabel.setText("Push!");
            }
        }
    }

    private void dealerTurn() {
        while (dealerScore < 17) {
            dealerHand.add(dealCard());
            dealerScore = calculateScore(dealerHand);
            updateDealerLabel();
        }
        hitButton.setEnabled(false);
        standButton.setEnabled(false);
        updateResultLabel();
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == hitButton) {
            playerHand.add(dealCard());
            playerScore = calculateScore(playerHand);
            updatePlayerLabel();
            if (playerScore > 21) {
                dealerTurn();
            }
        } else if (e.getSource() == standButton) {
            dealerTurn();
        } else if (e.getSource() == newGameButton) {
            for (Component component : playerLabel.getComponents()) {
                if (component instanceof JPanel) {
                    playerLabel.remove(component);
                }
            }
            for (Component component : dealerLabel.getComponents()) {
                if (component instanceof JPanel) {
                    dealerLabel.remove(component);
                }
            }
            resultLabel.setText("");
            newGame();
        }
    }

    public static void main(String[] args) {
        TwentyOneGame game = new TwentyOneGame();
        game.setVisible(true);
    }
}

此代码中用到了一个 `Card` 类，用于表示扑克牌，其中包括花色（`Suit`）和点数（`Rank`）两个枚举类型，以及获取对应图片的方法。

import javax.swing.*;
import java.awt.*;

public class Card {
    private final Rank rank;
    private final Suit suit;

    public Card(Rank rank, Suit suit) {
        this.rank = rank;
        this.suit = suit;
    }

    public Rank getRank() {
        return rank;
    }

    public Suit getSuit() {
        return suit;
    }

    public Image getImage() {
        String filename = "cards/" + rank.getValue() + suit.getName() + ".png";
        return new ImageIcon(filename).getImage();
    }

    public static Image getBackImage() {
        return new ImageIcon("cards/back.png").getImage();
    }
}

枚举类型 `Rank` 和 `Suit` 的定义如下：

public enum Rank {
    ACE(1, "A"), TWO(2, "2"), THREE(3, "3"), FOUR(4, "4"), FIVE(5, "5"), SIX(6, "6"),
    SEVEN(7, "7"), EIGHT(8, "8"), NINE(9, "9"), TEN(10, "10"), JACK(10, "J"), QUEEN(10, "Q"), KING(10, "K");

    private final int value;
    private final String name;

    Rank(int value, String name) {
        this.value = value;
        this.name = name;
    }

    public int getValue() {
        return value;
    }

    public String getName() {
        return name;
    }
}

public enum Suit {
    CLUBS("C"), DIAMONDS("D"), HEARTS("H"), SPADES("S");

    private final String name;

    Suit(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}