JButton position not functioning

Question

I'm new to java but know the basics of swing and a majority of the libraries and I was wondering why this practice program I recently made is not positioning a JButton at the right coordinates. I'm stumped. Here is the source code.

package game;

import java.awt.Color;
import java.awt.Image;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JButton;


public class TitleScreen extends JFrame
{
JFrame window = new JFrame();
JPanel screen = new JPanel();
JButton start = new JButton("Play Game");
JButton end = new JButton("Quit Game");
ImageIcon thing = new ImageIcon("lol.png");
Image pic = thing.getImage();

public TitleScreen()
{
 window.setTitle("Test");
 window.setSize(500,500);
 window.setBackground(Color.BLUE);
 window.setLocationRelativeTo(null);
 window.setResizable(false);
 window.setVisible(true);
}

public void canvas()
{
screen.setLayout(null);
window.add(screen);
start.setBounds(250,250,100,50);   
screen.add(start);  
}

public static void main(String[] args) 
{
TitleScreen TitleScreen = new TitleScreen();    
}

Rod_Algonquin · Answer 1 · 2014-06-14T14:30:27.917

2

That is because you didn't call the canvas method that is why it is not showing.

solution:

 public TitleScreen()

{
 window.setTitle("Test");
 window.setSize(500,500);
 window.setLocationRelativeTo(null);
 screen.setBackground(Color.BLUE);
 window.setVisible(true);
 canvas();
}

edited Jun 14 '14 at 14:30

answered Jun 14 '14 at 14:22

Rod_Algonquin

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Also why is that window.setBackground is not making the screen blue. Thanks again. – user2451511 Jun 14 '14 at 14:24
@user2451511 dont set the frames background instead set it to your jpanel. editted see above – Rod_Algonquin Jun 14 '14 at 14:30
2

wrong to change code lines ordering because you set canvas(); to alredy visible window.setVisible(true); – mKorbel Jun 14 '14 at 14:35
@Rod_Algonquin yes maybe wokrs in this case, but is about basics mistake, for more info to see code in answer by Braj – mKorbel Jun 14 '14 at 18:12

score 2 · Answer 2 · edited May 23 '17 at 11:49

Some points:

Don't use null layout instead use a proper layout that suits as per your need

It's worth reading about How to Use Various Layout Managers
Use SwingUtilities.invokeLater() to make sure that EDT is initialized properly.

Read more
- Why to use SwingUtilities.invokeLater in main method?
- SwingUtilities.invokeLater
Always call JFrame#setVisible(true) in the end after adding all the component.
Read more what is the purpose of JFrame setBackground

It should be like this:

public void canvas() {
    screen.setBackground(Color.BLUE);
    screen.add(start);
    window.add(screen);             
}

public TitleScreen() {
    ...
    canvas();
    window.setVisible(true); 
}

public static void main(String[] args) {        
    SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            TitleScreen TitleScreen = new TitleScreen();
        }
    });
}

JButton position not functioning

2 Answers2

Some points: