单击按钮时创建的项目在 JFrame 中不可见

Question

On button click, I am creating new JFrame, adding a JButton inside it and setting it visible. JFrame is visible but the JButton is not visible.

I tried finding answers on stackoverflow but everyone says to set the JFrame visible after adding the components. I did that also but still, the issue is not solved

below is button code

@Override
public void actionPerformed(ActionEvent arg0) {

  popup.showPopup();

}

I have made a class named "popup" with a show popup method.

Below is the code of popup.java class

package justin;

import java.awt.FlowLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class popupFrame {
    private JFrame f = new JFrame("Please wait...");

    public void showPopup() {
        System.out.println("Showing Popup");

        f.setSize(300, 150);

        f.setLayout(new FlowLayout());

        f.add(new JButton("Test"));

        f.setVisible(true);
    }
}

It should show the JFrame with items added in it on the click of button.

Please check the below link for my complete code:

https://github.com/jamesfdz/Justin-code

Answer 1

Since I can't see the rest of your code, I have posted an example instead.

public class ControlInterface{

    public ControlInterface() {
        JFrame frame = new JFrame();
        frame.setSize(400, 400);
        frame.add(new JButton("Test"));
        frame.setVisible(true);
    }
}

And the calling class:

public class BusinessLogic{

    public static void main(String[] args){
    JFrame frame = new JFrame();
    frame.setSize(300, 300);
    JButton button = new JButton("Popup");
    frame.add(button);
    frame.setVisible(true);

    button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            if(e.getSource() == button) {
                new ControlInterface();
            }
        }
    });
    }
}