swing jframe上书写一段文字用Graphics

Question

请把 line画在pan上谢谢
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class PaintTest extends JFrame{
JPanel pan=new JPanel();
    public PaintTest(){
        this.add(pan);
        pan.setToolTipText("myPan");
        this.setAlwaysOnTop(true);
        this.setTitle("LAFTest");
        this.setSize(400,250);
        this.setLocation(352,309);
        this.setVisible(true);
        this.setDefaultCloseOperation(3);
    }
    public static void main (String[] args) {
        PaintTest p= new PaintTest();
        
    }
}

Answer 1

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class PaintTest extends JFrame{
    JPanel pan=new JPanel();
    public PaintTest(){
        this.add(pan);
        pan.setToolTipText("myPan");
        this.setAlwaysOnTop(true);
        this.setTitle("LAFTest");
        this.setSize(400,250);
        this.setLocation(352,309);
        this.setVisible(true);
        this.setDefaultCloseOperation(3);
    }
    // 最好是把下面这段代码放到一个JPanel中, 即写一个类继承JPanel.
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
    
        g.drawLine(x1, y1, x2, y2); // 从点(x1, y1)画线到点(x2, y2)
    }    public static void main (String[] args) {
        PaintTest p= new PaintTest();
        
    }
}