Question

我想添加一个功能，以便当鼠标移过按钮时，它会添加一个投影。目前我只是想让机制起作用。我的游戏循环调用了一种我知道有效的更新方法，但无论如何它都是

    public void updateManager(double delta){
    mhandler.updateCoordinates();
    if(mhandler.getX() >= 144 && mhandler.getX() <= 444 && mhandler.getY() >= 784 && mhandler.getY() <= 980){
        oversp = true;
    }else{
        oversp = false;
    }
}

mhandler是我命名为MouseHandler类的东西。然后我有我的渲染方法

    public void render(){
    repaint();
}

然后是我的绘画方法

    public void paintComponent(Graphics g) {
    Graphics2D g2d = (Graphics2D) g;

    if(oversp){
        System.out.println("Is over button");
        g2d.setColor(Color.RED);
        g2d.fillRect(144, 784, 300, 169);
    }else{
        System.out.println("Not over button");
        g2d.setColor(Color.BLACK);
        g2d.fillRect(144, 784, 300, 169);
    }
}

当我运行该程序时，即使我在游戏循环中不断调用render（），它也只打印出不超过按钮两次。我真的不知道为什么不重新粉刷。任何帮助都非常有用！

这是我检测鼠标坐标

的方法

    private int x,y;

public MouseHandler(){
    x = 0;
    y = 0;
}

public void updateCoordinates(){
    PointerInfo a = MouseInfo.getPointerInfo();
    Point b = a.getLocation();
    x = (int) b.getX();
    y = (int) b.getY();
}

public int getX(){
    return x;
}

public int getY(){
    return y;
}

游戏循环代码

    public static void MenuLoop() {
    long lastLoopTime = System.nanoTime();
    final int TARGET_FPS = 60;
    final long OPTIMAL_TIME = 1000000000 / TARGET_FPS;
    long lastFpsTime = 0;
    int fps = 0;
    while (isrunning) {
        long now = System.nanoTime();
        long updateLength = now - lastLoopTime;
        lastLoopTime = now;
        double delta = updateLength / ((double) OPTIMAL_TIME);

        lastFpsTime += updateLength;
        fps++;

        if (lastFpsTime >= 1000000000) {
            System.out.println("(FPS: " + fps + ")");
            lastFpsTime = 0;
            fps = 0;
        }

        menu.render();
        menu.updateManager(delta);


        try {
            Thread.sleep((lastLoopTime - System.nanoTime() + OPTIMAL_TIME) / 1000000);
        } catch (Exception e) {

        }
    }

}public static void MenuLoop() {
    long lastLoopTime = System.nanoTime();
    final int TARGET_FPS = 60;
    final long OPTIMAL_TIME = 1000000000 / TARGET_FPS;
    long lastFpsTime = 0;
    int fps = 0;
    while (isrunning) {
        long now = System.nanoTime();
        long updateLength = now - lastLoopTime;
        lastLoopTime = now;
        double delta = updateLength / ((double) OPTIMAL_TIME);

        lastFpsTime += updateLength;
        fps++;

        if (lastFpsTime >= 1000000000) {
            System.out.println("(FPS: " + fps + ")");
            lastFpsTime = 0;
            fps = 0;
        }

        menu.render();
        menu.updateManager(delta);


        try {
            Thread.sleep((lastLoopTime - System.nanoTime() + OPTIMAL_TIME) / 1000000);
        } catch (Exception e) {

        }
    }

}

Answer 1

Event Dispatch Thread包含添加了所有AWT事件的队列。每当你调用repaint时，一个paint事件将在Event Dispatch Thread上排队。

因此，如果您在事件调度线程中处于无限循环中，那些绘制事件将永远排在队列中，等待无限循环结束。这就是永远不会调用paintComponent的原因。

解决方案是用Swing timer替换无限循环。

Timer timer = new Timer(1000 / TARGET_FPS, new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        //...
    }
});
timer.start();

Java图形没有重新绘制

1 个答案: