Question

Trying to use GridBagLayout.

I have the method called buildLabel. This creates three label.
Another method called addComponentsToFrame. This builds the frame and created a panel.
It also adds the three labels to the panel. Now I want to display what I have done.
How do I do display the frame. Here is my code!

@author eeua9b

public class GridBagLayoutDemo extends JFrame {

private JLabel label1;
private JLabel label2;
private JLabel label3;
private JFrame myFrame;
private JPanel p;

// build the Labels 
private void buildLabel() {

    label1 = new JLabel("Tables");
    label2 = new JLabel("Reports");
    label3 = new JLabel("Forms");

}

/**
 * build the frame 
 *add the labels to panel 
 *add the panel to the frame.
 * set the gridBagLayout
 */
private void addComponentsToFrame() {
    myFrame = new JFrame("My Frame");
    myFrame.setSize(600, 400);

    //this is underlined in red. 
    myFrame.getDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    p = new JPanel(new GridBagLayout());

    GridBagConstraints gbc = new GridBagConstraints();
    gbc.insets = new Insets(15, 15, 15, 15);

    p.add(label1, gbc);
    p.add(label2, gbc);
    p.add(label3, gbc);

    myFrame.add(p);

    myFrame.setVisible(true);
}

public static void main(String args[]) {
    //show the frame. this is underlined in red. 
    addcomponentsToFrame();
}
}

Answer 1

You need to create an instance of GridBagLayoutDemo first. Something like this will work.

public static void main(String args[]) {
    GridBagLayoutDemo demo = new GridBagLayoutDemo();
    demo.buildLabel();
    demo.addComponentsToFrame();
}