java - 如何在java中创建旋转的圆圈动画？

Question

我想在 JPanel 中间创建一个旋转圆圈，并且能够设置开始/停止旋转，还可以设置为可见/不可见。

有没有人知道怎么做或有任何现有的例子？

private static class RotatingCirclePanel extends JPanel {        
    protected void paintComponent(Graphics g) {

    }                      
}

这是一个例子。

已编辑:这是第一个版本。任何人都可以帮助将其制作成 gif 示例吗？

public class ProgressWheelPanel extends JPanel {
private double angleInDegrees = 1;
private Timer rotatingTimer;

public ProgressWheelPanel() {
    rotatingTimer = new Timer(100, new ActionListener() {
        //            @Override
        public void actionPerformed(ActionEvent e) {
            angleInDegrees = angleInDegrees +1;
            if (angleInDegrees == 360) {
                angleInDegrees = 0;
            }
            repaint();
        }
    });
    rotatingTimer.setRepeats(false);
    rotatingTimer.start();
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g.create();

    rotatingTimer.stop();

    g2d.clearRect(0, 0, getWidth(), getHeight());
    g2d.setBackground(Color.white);
    g2d.setColor(Color.black);
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.3f));
    g2d.setStroke(new BasicStroke(10f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_MITER));
    g2d.rotate(angleInDegrees * Math.PI / 180.0, getWidth() / 2, getHeight() / 2);
    g2d.drawLine(getWidth() / 2, getHeight() / 2, getWidth() / 2 + 100, getHeight() / 2);
    //**************************************************************************************
    AffineTransform transformer = new AffineTransform();
    transformer.translate(5,5);
    transformer.scale(2,2);
    g2d.getTransform().concatenate(transformer);
    //***************************************************************************************
    g2d.dispose();
    rotatingTimer.start();
}
public void start(){
    rotatingTimer.start();
}
public void stop(){
  rotatingTimer.stop();
}

public static void main(String[] args) {
    final ProgressWheelPanel demo = new ProgressWheelPanel();
    WebButton btnStrat= new WebButton("Start"),btnStop= new WebButton("Stop");
    btnStrat.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            demo.setVisible(true);
            demo.start();
        }
    });
    btnStop.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            demo.stop();
            demo.setVisible(false);
        }
    });
    JFrame frame = new JFrame();
    Container cp = frame.getContentPane();
    cp.add(demo,BorderLayout.CENTER);
    cp.add(btnStrat,BorderLayout.NORTH);
    cp.add(btnStop,BorderLayout.SOUTH);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(500, 500);
    frame.setLocation(500, 500);
    frame.setVisible(true);
}
}  

Answer 1

This answer包含用于创建基于图像的此类图标的代码片段。它基本上使用代码来旋转图标，以及触发旋转以获得动画效果的 Timer。