Question

JAVA中按上下左右键怎么让面板里面的东西八个方向移动？

用键盘监听

Answer 1

//重写JPanel
import java.awt.Graphics;

import javax.swing.JPanel;

public class MyPanel extends JPanel {

public static int x = 10;
public static int y = 10;

@Override
public void paint(Graphics g) {
g.drawRect(x, y, 30, 30);
}

}

//程序入口
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JFrame;

public class MyFrame extends JFrame{
private MyPanel mp;
public MyFrame() {
mp = new MyPanel();
this.add(mp);
this.setVisible(true);
this.setBounds(400, 200, 500, 500);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.addKeyListener(new KeyAdapter(){
public void keyPressed(KeyEvent e){
if(e.getKeyCode()==38){
MyPanel.y -= 10;
mp.repaint();
}else if(e.getKeyCode()==40){
MyPanel.y += 10;
mp.repaint();
}else if(e.getKeyCode()==37){
MyPanel.x -= 10;
mp.repaint();
}else if(e.getKeyCode()==39){
MyPanel.x += 10;
mp.repaint();
}
}
});
}

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

Answer 2

每个键都对应一个编码符event.keyCode，比如回车键是13，上下左右忘了，你查一下，然后在四个键的onkeypress（）事件里面设置，当为上方向时，把面板的坐标上移。。。。