JButton display issue - swing

Question

I have created a JFrame by creating a class(Display.java) that extends JFrame class. In that class I have created a JPanel object.
class Display extends JFrame {
JPanel jp= new JPanel();
And in another class(TestBroadCastNode.java) I am adding JButtons to that JPanel by using reference to the class Display as shown below:
class TestBroadCastNode {
Display disp;
Graphics g =disp.getGraphics();
JButton bt = new JButton("One");
disp.jp.add(bt);
}
Now I am not able to display the buttons. Help me.... If you want I can send you the complete file.

Answer 1

I tried to match your code as close as possible, but since you only gave limited snippets I had to make some assumptions. But the following code shows the button just fine:
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TestClass {
public static class Display extends JFrame {
public JPanel panel = new JPanel( );
public Display(){
super( "TestFrame");
getContentPane().add( panel );
}
}
public static class TestBroadCastNode{
Display display;
public TestBroadCastNode( Display aDisplay ) {
display = aDisplay;
display.panel.add( new JButton( "One" ) );
}
}
public static void main( String[] args ) throws Exception {
SwingUtilities.invokeLater( new Runnable() {
public void run() {
Display display = new Display();
display.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
new TestBroadCastNode( display );
display.pack();
display.setVisible( true );
}
} );
}
}