java - 如何更改计时器内部油漆的颜色

Question

这是我关心的代码部分，当我尝试使用计时器再次更改 squaresToDisplay 对象的颜色时，它使框架变白(空白)，但它只工作了 1 次。所以当我运行这段代码时，它会做我想做的事 1 次然后让屏幕空白。我想知道是什么原因造成的。我自己的假设是，当我启动 SQTimer 时，我可能会阻止 EDT，在这种情况下，我不知所措，因为我不知道足够的 java 来解决这个问题:/

private Timer SQTimer;
startButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {

        //Code that removes unrelated things from the frame

        final SquareObjects squaresToDisplay = new SquareObjects(x,y);//Creates the Object based on GUI width and height
        squaresToDisplay.setFocusable(true);
        squaresToDisplay.setVisible(true);//Allows it to be visible
        frame.add(squaresToDisplay);//Adds it to the frame
        SQTimer = new Timer(1000, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e){
                squaresToDisplay.repaint();
                System.out.println("Repainted");
                }
        });
        System.out.println("Completed adding pixels");
        SQTimer.setRepeats(true);
        SQTimer.start();
    } 
});
    @Override
    protected void paintComponent(Graphics g){
        super.paintComponent(g);
        System.out.println("Beginning of paintComponent");
        System.out.println("Completed making the Graphics objects");
        for(int i = 0;i<(x*y)/64;i++){
        if(xInterceptLocation == 0){
            g.fillRect(xInterceptLocation, yInterceptLocation, 8, 8);
            xInterceptLocation += 8;
        }else{
            Color newColor = changingColors();
            g.setColor(newColor);
            g.fillRect(xInterceptLocation, yInterceptLocation, 8, 8);
            xInterceptLocation += 8;
            if(xInterceptLocation == 1920){
                xInterceptLocation = 0;
                yInterceptLocation += 8;
            }
        }
    }
}

澄清一下，这些方法在不同的类中，第一个在名为 GUI 的类中，而第二个在名为 SquareObjects 的类中

Answer 1

问题是 yInterceptLocation 从未设置回 0，因此当程序重新绘制时，它继续添加 8，从而使屏幕空白，因为它超出了帧边界。

@Override
protected void paintComponent(Graphics g){
    super.paintComponent(g);
    System.out.println("Beginning of paintComponent");

    System.out.println("Completed making the Graphics objects");
    //yIntercept needs to be reinitialized when the repaint(); is called again
    if(yInterceptLocation == 1080){
        yInterceptLocation = 0;
    }

    for(int i = 0;i<(x*y)/64;i++){
            if(xInterceptLocation == 0){//If i == 0 then it wont add 8 first (thus preventing a gap)
            g.fillRect(xInterceptLocation, yInterceptLocation, 8, 8);
            xInterceptLocation += 8;
        }else{//Any other time we want to add 8 to space out the squares
            Color newColor = changingColors();
            g.setColor(newColor);
            g.fillRect(xInterceptLocation, yInterceptLocation, 8, 8);
            xInterceptLocation += 8;
            if(xInterceptLocation == 1920){//if xInterceptLocation = 1920 then it adds 8 to yIntercept and sets x to 0 (creating a new line)
                xInterceptLocation = 0;
                yInterceptLocation += 8;
            }
        }
    }
}

感谢 HoverCraft Full Of Eels，注意到它没有重新初始化