JButton在图像后面显示

Question

So hello there :), this is my fist post here. Lets get right into it: My problem: I put a calculator as a background image, than added a JButton to it. My Problem(s):

When I start the program the calculator is quickly shown, then it vanishes and the button is shown When I resize the window, the calculator shows up and the button dissapears

How can I make this work?

Heres my code:

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

public class Calculator extends JFrame {
    private ImageIcon image;
    private JLabel label;


Calculator() {


    image = new ImageIcon(getClass().getResource("TStiny.png"));
    label = new JLabel(image);
    add(label);
}

public static void main (String args[]) {

    Calculator gui = new Calculator();
    gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    gui.setTitle("Texas Instruments TI-30XIIS");
    gui.pack();
    gui.setVisible(true);

    JPanel panel = new JPanel();
    gui.add(panel);

    JButton button7 = new JButton();
    button7.setIcon(new ImageIcon(Calculator.class.getResource("button_7.png")));
    button7.setVisible(true);
    button7.setBorderPainted(false);
    button7.setBounds(90, 445, 45, 35);
    panel.add(button7);

}

Thanks in advance! :)

Answer 1

You need to specify the layout and eventual position to which you want to add the component. JFrame uses BorderLayout by default.

If you want to use the default behavior, you should put a position on which to place the component:

public class Calculator extends JFrame {
    private ImageIcon image;
    private JLabel label;


    Calculator() {
        image = new ImageIcon(getClass().getResource("TStiny.png"));
        label = new JLabel(image);
        add(label, BorderLayout.LINE_START);
    }

    public static void main(String args[]) {

        Calculator gui = new Calculator();
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        gui.setTitle("Texas Instruments TI-30XIIS");
        gui.pack();
        gui.setVisible(true);

        JPanel panel = new JPanel();
        gui.add(panel, BorderLayout.LINE_END);

        JButton button7 = new JButton();
        button7.setIcon(new ImageIcon(Calculator.class.getResource("button_7.png")));
        button7.setVisible(true);
        button7.setBorderPainted(false);
        button7.setBounds(90, 445, 45, 35);
        panel.add(button7);

    }
}

Another option is to specify a layout that does not want to specify a position - such as FlowLayout :

public class Calculator extends JFrame {
    private ImageIcon image;
    private JLabel label;


    Calculator() {
        setLayout(new FlowLayout());

        image = new ImageIcon(getClass().getResource("TStiny.png"));
        label = new JLabel(image);
        add(label);
    }

    public static void main(String args[]) {

        Calculator gui = new Calculator();
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        gui.setTitle("Texas Instruments TI-30XIIS");
        gui.pack();
        gui.setVisible(true);

        JPanel panel = new JPanel();
        gui.add(panel);

        JButton button7 = new JButton();
        button7.setIcon(new ImageIcon(Calculator.class.getResource("button_7.png")));
        button7.setVisible(true);
        button7.setBorderPainted(false);
        button7.setBounds(90, 445, 45, 35);
        panel.add(button7);

    }
}