How to make JFrame background and JPanel transparent with only image showing

java, jframe, jpanel, swing

Solution

You need to set the `ImagePanel` to `setOpaque(false)`

 public ImagePanel() {
        setOpaque(false);

Also you were getting the exception because you need to `setUndecorate(true)` before you `pack();`

 JFrame frame = new JFrame();
 frame.add(new ImagePanel());
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 frame.setUndecorated(true);
 frame.pack(); 
 frame.setBackground(new Color(0, 0, 0, 0)); 
 frame.setVisible(true);

Those are the only two things I changed and it works. Also I got rid of the `setSize()`

Also use `frame.setLocationRelativeTo(null);` after `pack()` to center the frame.

Here's is an example (just for future readers, since I think this may be a popular question)

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.*;

public class CircleSplashScreen {

    public CircleSplashScreen() {
        JFrame frame = new JFrame();
        frame.getContentPane().add(new ImagePanel());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setUndecorated(true);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setBackground(new Color(0, 0, 0, 0));
        frame.setVisible(true);
    }

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

    @SuppressWarnings("serial")
    public class ImagePanel extends JPanel {

        BufferedImage img;

        public ImagePanel() {
            setOpaque(false);
            setLayout(new GridBagLayout());
            try {
                img = ImageIO.read(new URL("http://www.iconsdb.com/icons/preview/royal-blue/stackoverflow-4-xxl.png"));
            } catch (IOException ex) {
                Logger.getLogger(CircleSplashScreen.class.getName()).log(Level.SEVERE, null, ex);
            }

        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(500, 500);
        }
    }
}

Problem

Hey I am trying to make a some kind of launcher and the "window" must be transparent because I want the image I am using to be the design of it if you understand what I mean. I tried to do `setUndecorated(true);` and `setBackground(new Color(0, 0, 0, 0));` but it just looked weird. Here is a picture on how it looks: http://prntscr.com/2pqohq Here is my code: ``` import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.GridBagLayout; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.net.MalformedURLException; import java.util.logging.Level; import java.util.logging.Logger; import javax.imageio.ImageIO; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; /** * * Our Launcher for the client * * @author Daniel <Skype: daniel.gusdal> * * Current Date: 5. feb. 2014 Current Time: 14:29:54 * Project: 742 client. File Name: Launcher.java * */ public class Launcher2 { public Launcher2() { JFrame frame = new JFrame(); frame.getContentPane().add(new ImagePanel()); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //frame.pack(); //had to remove, got an error from it... frame.setUndecorated(true); //transparent frame.setBackground(new Color(0, 0, 0, 0)); //transparent frame.setVisible(true); frame.setSize(1080, 550); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable(){ public void run() { new Launcher2(); } }); } @SuppressWarnings("serial") public class ImagePanel extends JPanel { BufferedImage img; public ImagePanel() { setLayout(new GridBagLayout()); try { img = ImageIO.read(new File("C:/Users/Daniel/Pictures/Launcher3.png/")); } catch (MalformedURLException ex) { Logger.getLogger(Launcher2.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(Launcher2.class.getName()).log(Level.SEVERE, null, ex); } } /** * Draws the image and sets the image dimension */ @Override protected void paintComponent(Graphics g) { super.paintComponent(g); //g.drawImage(img, 100, 100, 1080, 550, this); g.drawImage(img, 0, 0, getWidth(), getHeight(), this); } /** * Sets the JPanel dimension */ public Dimension getPreferredSize() { return new Dimension(1080, 550); } } } ```

Original source