Question

java中Jpanel中的paint函数会自动被调用吗？

以下程序在jbuilder中运行paint函数没有被调用，为什么啊？
package game_ball;

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

/**
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2007</p>
* <p>Company: </p>
* @author not attributable
* @version 1.0
*/

public class Panel_Game extends JPanel {
//Graphics g;
public void paint (Graphics g){System.out.println("hi");
Brick b=new Brick(g);
b.DrawBricks();
}
BorderLayout borderLayout1 = new BorderLayout();

public Panel_Game() {
super();
try {
jbInit();
}
catch(Exception ex) {
ex.printStackTrace();
}
}
void jbInit() throws Exception {
this.setLayout(borderLayout1);
}
}

Answer 1

第一次会自动调用,如果要改变就要调用repaint()方法