Question

I am trying to add and remove panel on a swing window JFrame Container with the help of following code. JPanel is being added if it added in the constructor but its not being added runtime .

import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

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

class test extends JFrame implements ActionListener {
    test() {
        Container cp = this.getContentPane();
        JButton b1 = new JButton("add");
        JButton b2 = new JButton("remove");
        cp.add(b1);
        cp.add(b2);
        b1.addActionListener(this);
        b2.addActionListener(this);
    }

    public void actionPerformed(ActionEvent ae) {
        if (ae.getActionCommand().equals("add")) {
            panel1 frm = new panel1();
            cp.add(frm);
        }
        if (ae.getActionCommand().equals("remove")) {
            remove(frm);
        }
    }

    public static void main(String args[]) {
        test t1 = new test();
        t1.show(true);
    }
}

class panel1 extends JPanel {
    panel1() {
        JButton b1 = new JButton("ok");
        add(b1);
    }
}

Answer 1

1. for your concept (after remove or add JPanel to JFrame) have to call validate() & repaint() to JFrame

2. better could be to use CardLayout