Question

Im very new to java. I don’t know what’s wrong with my frame. I set the size to 300 and 200.
What Im seeing is a short and fat stick like thing.

Below is my code:

import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;

import javax.swing.JFrame;

public class BicycleDemo extends JFrame {
    /**
     * The serialVersionUID.
     */
    private static final long serialVersionUID = -4541236176053545919L;

    public static void createGUI () {
            JFrame jFrame = new JFrame("JFrame Demo");
            jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            Container container = jFrame.getContentPane();
            container.setLayout(new FlowLayout());
            container.setBackground(Color.BLACK);

            jFrame.setSize(300, 200);
            jFrame.setResizable(false);
            jFrame.pack();
            jFrame.setVisible(true);
    }

    public static void main(String[] args) {
            javax.swing.SwingUtilities.invokeLater(new Runnable() {
                 public void run() {
                      createGUI ();
                 }
            });
    }
}

Please help.

Answer 1

You are calling pack(). pack() method resizes the frame to the smallest possible size to hold all the elements. So in fact you set the size to 200 x 300 and then resize the frame once more with pack().

Be aware however, that “hold all elements” is calculated by their preferred size, which can be just 0x0 pixels in a lot of cases.