Question

JPanel的颜色怎么不行啊，求高手指教。

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

public class MyselfFrame extends JFrame
{
public MyselfFrame()
{
JFrame fr1=new JFrame();
setLayout(new BorderLayout());
setSize(1000,700);

JPanel p1=new JPanel():
JPanel p2=new JPanel();
JPanel p3=new JPanel();
JPanel p4=new JPanel();

fr1.add(p1,BorderLayout.NORTH);
fr1.add(p2,BorderLayout.SOUTH);
fr1.add(p3,BorderLayout.WEST);
fr1.add(p4,BorderLayout.EAST);

p1.setBackground(Color.yellow);
p2.setBackground(Color.red);
p3.setBackground(Color.blue);
p4.setBackground(Color.green);

setVisible(true);

}
}

Answer 1

JFrame fr1 = new JFrame();去掉
fr1.add改为add