Функция setVisible(true); используется для отображения кадра. Создайте объект нужного кадра и вызовите эту функцию. Как то так
//The applications first or the main frame
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MainFrame extends JFrame {
private JButton myFirstButton;
private JButton mySecondButton;
// Constructor for a new frame
public MainFrame {
super("My First Button Program");
myFirstButton = new JButton("First Frame");
myFirstButton.setFont(new Font( "Arial", Font.BOLD, 18));
myFirstButton.setBackground(Color.red);
mySecondButton = new JButton("New Frame");
mySecondButton.setFont(new Font( "Arial", Font.BOLD, 18));
mySecondButton.setBackground(Color.green);
Container c = getContentPane();
FlowLayout fl = new FlowLayout(FlowLayout.LEFT);
c.setLayout(fl);
c.add (myFirstButton);
c.add (mySecondButton);
ButtonHandler handler = new ButtonHandler(); //creation of a new Object
myFirstButton.addActionListener(handler); // Attach/register handler to myFirstButton
mySecondButton.addActionListener(handler); //Attach/register handler to mySecondButton
setSize(400, 300);
show();
}
public static void main(String [] args) {
// Make frame
MainFrame f = new MainFrame();
f.addWindowListener(
new WindowAdapter() {
public void windowClosing(WindowEvent e) {
// This closes the window and terminates the
// Java Virtual Machine in the event that the
// Frame is closed by clicking on X.
System.out.println("Exit via windowClosing.");
System.exit(0);
}
}
);
} // end of main
// inner class for button event handling
private class ButtonHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == myFirstButton) {
new NewFrame1();
}
if (e.getSource() == mySecondButton) {
new NewFrame2();
}
}
} // end of inner class
} // end of outer class
Открываемая рамка для первой кнопки
//import statements here
public class NewFrame1 extends JFrame implements ActionListener
{
//initialises the frame and opens it
public NewFrame1()
{
JButton open = new JButton("New Window");
open.addActionListener(this);
add(open);
setVisible(true);
}
public void actionPerformed(ActionEvent event)
{
//code for the new frame
}
}
Открываемая рамка для второй кнопки
//import statements here
public class NewFrame2 extends JFrame implements ActionListener
{
//initialises the frame and opens it
public NewFrame2()
{
JButton open = new JButton("New Window");
open.addActionListener(this);
add(open);
setVisible(true);
}
public void actionPerformed(ActionEvent event)
{
//code for the new frame
}
}