Question

编写一个java程序，显示一个面板的背景色，当按下鼠标键背景色为黑色，释放鼠标时背景色为白色

Answer 1

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class B {

/**
* @param args
*/
public static void main(String[] args) {

JFrame f = new JFrame();

final JPanel p = new JPanel();

f.add(p, BorderLayout.CENTER);

p.addMouseListener(new MouseListener(){

public void mouseClicked(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}

public void mousePressed(MouseEvent e) {
p.setBackground(Color.black);
}

public void mouseReleased(MouseEvent e) {
p.setBackground(Color.white);
}

});

f.setSize(200, 300);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

}