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我编写了程序来绘制轮子(有 6 段的圆圈)和不同颜色的每个段。并为轮子设置动画..

这是代码:

    public class ExamWheel extends JFrame implements ActionListener{
        JButton b_start = new JButton("Start");
        JButton b_stop = new JButton("Stop");
        Thread th;
        Boolean doDraw = true;

        public ExamWheel(){
            setSize(400,400);
            setVisible(true);
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setLocationRelativeTo(null);
            setTitle("Wheel..");
            //add(b_start);
            this.setLayout (new FlowLayout());
            this.add(b_stop);
            b_start.addActionListener(this);
        }

        public void actionPerformed(ActionEvent e) {
            if(e.getSource()==b_start)
                doDraw=true;
        }

        public void paint(Graphics graphics) {
        if (doDraw){
            super.paint(graphics);
            Graphics2D g = (Graphics2D) graphics;
            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

            try{
            // draw the circle
            for(int i=0; ; i=i+1){
                g.setColor(Color.CYAN);
                g.fillArc(50, 50, 300, 300, i+0, 60);
                th.sleep(1);
                g.setColor(Color.red);
                g.fillArc(50, 50, 300, 300, i+60, 60);
                th.sleep(1);
                g.setColor(Color.green);
                g.fillArc(50, 50, 300, 300, i+120, 60);
                th.sleep(1);
                g.setColor(Color.blue);
                g.fillArc(50, 50, 300, 300, i+180, 60);
                th.sleep(1);
                g.setColor(Color.gray);
                g.fillArc(50, 50, 300, 300, i+240, 60);
                th.sleep(1);
                g.setColor(Color.pink);
                g.fillArc(50, 50, 300, 300, i+300, 60);
                th.sleep(1);
            }
            }
            catch(InterruptedException e){
                Thread.currentThread().interrupt();
            }
        }
        }

        public static void main(String[] args) {
            ExamWheel f = new ExamWheel();
        }

    }

问题:它是无限循环,我无法停止它或关闭框架。

所以我有想法:

我创建了值为true的布尔变量(doDraw),并添加了JButton,当单击按钮时,变量将变为false,在paint()方法中,我将首先使用paint()的if条件

问题:我无法使用paint() 将JButton 添加到Frame,我该怎么办?

注意:我尝试使用paintComponent(),但循环(for with thread)不起作用。

解决了感谢 Pete Kirham

我添加了 Timer 并用paintComponent() 替换了paint()

public class ExamWheel extends JPanel implements ActionListener {
    int i=0;
    Timer tm = new Timer(10, this);
    public void paintComponent(Graphics graphics) {
        super.paintComponent(graphics);
        Graphics2D g = (Graphics2D) graphics;
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        g.setColor(Color.CYAN);
        g.fillArc(50, 50, 300, 300, i+0, 60);
        g.setColor(Color.red);
        g.fillArc(50, 50, 300, 300, i+60, 60);
        g.setColor(Color.green);
        g.fillArc(50, 50, 300, 300, i+120, 60);
        g.setColor(Color.blue);
        g.fillArc(50, 50, 300, 300, i+180, 60);
        g.setColor(Color.gray);
        g.fillArc(50, 50, 300, 300, i+240, 60);
        g.setColor(Color.pink);
        g.fillArc(50, 50, 300, 300, i+300, 60);
        tm.start();
    }
    public void actionPerformed(ActionEvent e) {
        i++;
        repaint();
    }
    public static void main(String[] args) {
        ExamWheel wh = new ExamWheel();
        JFrame jf = new JFrame();
        jf.setSize(500,500);
        jf.setResizable(false);
        jf.setVisible(true);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setLocationRelativeTo(null);
        jf.setTitle("Wheel..");
        jf.add(wh);
    }
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1 回答 1

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您需要从 paintComponent 返回以允许运行 gui 的线程执行其他操作,例如响应按钮事件或实际将图形内容放到屏幕上。

使用计时器使组件无效 - 请参阅http://docs.oracle.com/javase/tutorial/uiswing/misc/timer.html并根据当前时间更新动画,例如当前毫秒模 5000 将给出每五秒重复一次的循环。

于 2012-11-23T20:45:36.637 回答