Java：在JFrame上添加背景图片

Question

I'm making a gui program everything going right but add background image in frame so i take jpanel private variable.Also i add image in src which is

but how to use this jpanel variable to add background image in frame.
Code:

public class App extends JFrame{

private JPanel panel;
private JTextField field1;
private JTextField print;
private JLabel label;
private JLabel label2;
private JButton button;




public App(){
    super();
getContentPane().setLayout(null);



label = new JLabel("Value");
label.setForeground(Color.RED);
label.setFont(new Font("SansSerif", Font.PLAIN, 18));
label.setBounds(178, 46, 51, 26);
getContentPane().add(label);


label2 = new JLabel("Print");
label2.setForeground(Color.RED);
label2.setFont(new Font("SansSerif", Font.PLAIN, 18));
label2.setBounds(178, 143, 42, 26);


getContentPane().add(label2);






field1 = new JTextField();
field1.setBounds(178, 72, 76, 26);


getContentPane().add(field1);



print = new JTextField();
print.setBounds(178, 181, 77, 26);
getContentPane().add(print);



button = new JButton("Click");
button.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent arg0) {

        String w= field1.getText();
        print.setText(w);



    }
});
button.setBounds(178, 219, 77, 26);
getContentPane().add(button);



}

}

Main Method:

public class Main {

public static void main(String[] args) {



    App object = new App();
    object.setSize(450, 400);   
    object.setDefaultCloseOperation(object.EXIT_ON_CLOSE);
    object.setLocationRelativeTo(null);
    object.setVisible(true);        
       }


}

Answer 1

You have set Layout to null which is making a problem. Whenever we make layout null we have to set bounds for it.

Folow this method:

1. first of all copy your background image and paste in src of code

2. than set layout to borderlayout like this:

   setLayout(new BorderLayout());

3. now add this code:

   setContentPane(new JLabel new ImageIcon(getClass().getResource("image.jpg"))));

Note: add your image name here "image.jpg"