Question

我刚刚开始学习编程applet和java GUI，我试图制作一个简单的游戏。目前，我有主要类（游戏）和玩家类（玩家）我让玩家绘制到屏幕上，但我很难让关键事件发挥作用，任何帮助表示赞赏！

玩家图像显示完全正常，但当我完全按下按键时位置不会改变。

编辑：为播放器发布了错误代码，已更新

Game.java：

public class Game extends Applet {

    Player player;

    @Override
    public void init() {
        player = new Player(this);
        this.setSize(800, 600);
        addKeyListener(player);
    }

    @Override
    public void paint(Graphics g) {        
        player.paint(g);
    }



}

Player.java：

public class Player implements KeyListener {

    Game game;
    Image image;
    int x;
    int y;

    public Player(Game game) {
        this.game = game;
        x = 0;
        y = 0;
        image = game.getImage(game.getCodeBase(), "images/Player.png");
    }

    public void paint(Graphics g) {
        g.drawImage(image, x, y, game);
    }

    @Override
    public void keyTyped(KeyEvent e) {
        return;
    }

    @Override
    public void keyPressed(KeyEvent e) {
        switch (e.getKeyCode()) {
            case KeyEvent.VK_A:
                x -= 1;
                break;
            case KeyEvent.VK_D:
                x += 1;
                break;
            case KeyEvent.VK_S:
                y += 1;
                break;
            case KeyEvent.VK_W:
                y -= 1;
                break;
        }
        game.repaint();
    }

    @Override
    public void keyReleased(KeyEvent e) {
        return;
    }
}

Answer 1

小组可能没有焦点，或者无法集中注意力。

试试这段代码。我将键更改为左/右/上/下箭头。为简单起见，我将其保留为基于AWT的小程序。

// <applet code='Game' width=400 height=100></applet>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class Game extends Applet implements KeyListener {

    Player player;

    @Override
    public void init() {
        player = new Player(getImage(32));
        addKeyListener(this);
        setFocusable(true);
        requestFocusInWindow();
    }

    @Override
    public void paint(Graphics g) {
        player.paint(g);
    }

    public Image getImage(int size) {
        Image img = createImage(size,size);
        Graphics g = img.getGraphics();
        g.setColor(Color.RED);
        g.fillRect(0,0,size,size);

        g.dispose();

        return img;
    }

    @Override
    public void keyTyped(KeyEvent e) {
        return;
    }

    @Override
    public void keyPressed(KeyEvent e) {
        switch (e.getKeyCode()) {
            case KeyEvent.VK_LEFT:
                player.x -= 1;
                break;
            case KeyEvent.VK_RIGHT:
                player.x += 1;
                break;
            case KeyEvent.VK_DOWN:
                player.y += 1;
                break;
            case KeyEvent.VK_UP:
                player.y -= 1;
                break;
        }
        repaint();
    }

    @Override
    public void keyReleased(KeyEvent e) {
        return;
    }
}

class Player {

    Image image;
    int x;
    int y;

    public Player(Image image) {
        x = 0;
        y = 0;
        this.image = image;
    }

    public void paint(Graphics g) {
        g.drawImage(image, x, y, null);
    }

}

KeyListener事件显然没有在java applet中触发

1 个答案: