Java NetBeans IDE - JPanel 中的动画闪烁

Question

我目前正在 NetBeans 中学习 Java 动画和图形。

我决定从 JPanel 中的简单球运动开始。

我在修复闪烁问题时遇到一些问题。我看过很多论坛，但大多数都是使用双缓冲的 AWT，但我后来知道 SWING 组件不需要双缓冲。我尝试过 - 使用 repaint() 和 .clearRect()。

在这 2 个中，我发现使用 .clearRect() 给了我更好的结果，但并不是一直无缝无闪烁动画。所以我想知道是否有更好的方法消除闪烁。

这是我的代码:

public class NewJFrame extends javax.swing.JFrame {

int x;
int y;
int xspeed = 1;
int yspeed = 1;
int width;
int height;
Graphics g;

    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() {
        initComponents();
    }                             

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
g = jp.getGraphics();
width = jp.getWidth();
height = jp.getHeight();
final Timer timerCHK = new Timer();
timerCHK.schedule(new TimerTask() {
    public void run() {
        move();
        time();

    }
}, 1000, 10);

    }                                        
void time() {
    final Graphics g = jp.getGraphics();
    final Timer timerCHK = new Timer();
    timerCHK.schedule(new TimerTask() {
        public void run() {
            g.clearRect(0, 0, jp.getWidth() - 3, jp.getHeight() - 3);

        }
    }, 1000, 12);
}

void move() {
    x = x + xspeed;
    y = y + yspeed;
    Graphics mk = jp.getGraphics();
    if (x < 0) {
        x = 0;
        xspeed = -xspeed;
    } else if (x > width - 20) {
        x = width - 20;
        xspeed = -xspeed;
    }

    if (y < 0) {
        y = 0;
        yspeed = -yspeed;
    } else if (y == height - 20) {
        y = height - 20;
        yspeed = -yspeed;
    }

    mk.drawOval(x, y, 20, 20);

}
    public static void main(String args[]) {

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
}

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class NewJFrame extends JFrame {

    private JPanel jp;
    private Timer timer;

    public NewJFrame() {
        initComponents();

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        this.setLocationByPlatform(true);
        timer.start();
    }

    public void initComponents() {
        ActionListener al = new ActionListener() {

            public void actionPerformed(ActionEvent evt) {
                jp.repaint();
            }
        };
        timer = new Timer(50,al);

        jp = new JPanel() {

            int x;
            int y;
            int xspeed = 1;
            int yspeed = 1;

            Dimension preferredSize = new Dimension(300, 100);

            @Override
            public Dimension getPreferredSize() {
                return preferredSize;
            }

            @Override
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                this.move();
                Graphics2D g2 = (Graphics2D)g;
                g2.setRenderingHint(
                        RenderingHints.KEY_ANTIALIASING, 
                        RenderingHints.VALUE_ANTIALIAS_ON);
                g.drawOval(x, y, 20, 20);
            }

            void move() {
                x = x + xspeed;
                y = y + yspeed;
                if (x < 0) {
                    x = 0;
                    xspeed = -xspeed;
                } else if (x > getWidth() - 20) {
                    x = getWidth() - 20;
                    xspeed = -xspeed;
                }

                if (y < 0) {
                    y = 0;
                    yspeed = -yspeed;
                } else if (y == getHeight() - 20) {
                    y = getHeight() - 20;
                    yspeed = -yspeed;
                }
            }
        };
        jp.setBackground(Color.ORANGE);

        this.add(jp);
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {

            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
}