JButton won't display

Question

I've created a simple program with the Robot class which generates a screen capture of your computer. It creates the screen capture when you click on a JButton.

I've tried to make the JFrame disappear when the screen capture is being made. Unfortunately, the JButton won't display... Can you tell me what is wrong with my code?

package Threads;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.*;

public class ScreenCapture extends JFrame implements ActionListener{

private JButton b;

public ScreenCapture() throws Exception{
    this.setTitle("Etfeld");
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    this.setVisible(true);
    this.pack();
    this.setResizable(false);
    this.setLocation(1366/2-100,678/2);

    ImageIcon jamil=new ImageIcon("Logo.png");
    Image logo=jamil.getImage();
    this.setIconImage(logo);

    JPanel jp=new JPanel();
    b=new JButton("Capture!");
    b.addActionListener(this);
    this.add(jp);
    jp.add(b);

}

@Override
public void actionPerformed(ActionEvent ae) {
    Object obj=ae.getSource();
    if(obj instanceof JButton){
        try {
            Robot robot = new Robot();
            this.setVisible(false);
            BufferedImage im=robot.createScreenCapture(new Rectangle(0,0,1366,768));

                    Toolkit.getDefaultToolkit().beep();
                    this.setVisible(true);
                    File outputfile = new File("saved.png");
                    ImageIO.write(im, "png", outputfile);
                } catch (Exception v) {v.printStackTrace();}
    }

}

public static void main(String []args) throws Exception{
    ScreenCapture sc=new ScreenCapture();
}
}

Answer 1

You need to rearrange the calls to your methods. You should call pack() just before making the frame visible; after you have added all your UI components.
Then, use setVisible(true) to make the JFrame visible.