My problem is setting the size of the JButton. I want it to be a little button centered below the "Hello World" JLabel field (as it is now it spans the full width of the JFrame). I am unsure what is causing the setPreferredsize to be ignored. I am an ameture/novice Java Developer and appriciate any help and all help. My code is below error free:

/* Author: Ashley
 * This program will display a basic JFrame, JLabel, and JButton.
 * The JLabel will display "Hello World and the JButton will close the program
 */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
 *
 * @author Ashley
 */
public class gui extends JFrame implements ActionListener {


    public static void main(String[] args) {  //main arguments string

        gui gui = new gui();  // calls gui which holds all the GUI data

        /**
         *  method declaration for the gui 
         */
    }

    public gui() {

        String text = "Hello World!";  // creates a string for hello world
        JButton button; // names a JButton                

        JFrame frame = new JFrame("My GUI"); // creates a JFrame named fram

        frame.setSize(250, 150); // sets frame size 
        frame.setVisible(true); // makes frame visable
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //creates default close functions

        JPanel tpanel = new JPanel();  //creats a JPanel to hold the JLabel
        JLabel label = new JLabel( text ); //creats a JLabel
        label.setHorizontalAlignment(SwingConstants.CENTER); // sets JLabel middle and centered


        tpanel.add(label); // adds JLabel to the panel

        button = new JButton("OK");    // creates JButton
        Dimension bd = new Dimension(50, 50);
        button.setPreferredSize(bd);

        button.addActionListener(new ActionListener() { // add an action listener with inner class to declare JButton event
            @Override
            public void actionPerformed(ActionEvent e) { //inner class assigns action to button
                System.exit(0);
            }
        });

        frame.add(label, BorderLayout.CENTER); // addes JLabel to the JFrame
        frame.add(button, BorderLayout.SOUTH);// adds JButton to the JFrame



    }

    @Override  // an override for inner class, ensures that the button action will run. 
    public void actionPerformed(ActionEvent ae) {
    }
}

Do not add button into contentPane of JFrame directly instead create a JPanel (with FlowLayout) and add that button in it.

JPanel bottom=new JPanel();
bottom.add(button);  
frame.add(bottom, BorderLayout.SOUTH);

Excellent thank you! Worked perfectly and helped put a little light into building GUI's. This is my first Java GUI. I am working on my next class assignment and needed to make sure I could size buttons accordingly. =)

Thanks again ~ Problem solved!

This article has been dead for over six months. Start a new discussion instead.