如何在JFrame上放置多张图片？

Question

I'm having a problem putting multiple images on a JFrame. I already added a picture on the JFrame as the primary background. But when I try to put another image for the logo of my program, it doesn't show up. Can someone please help me? thanks.

PS I'm using the Container class in my JFrame.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.event.*;
import java.io.*;
import java.awt.Container;

public class logIn extends JFrame
{

    Random rand = new Random();
int n2 = (int) (1+Math.random()*255);
int n1 = rand.nextInt(n2);
int n3 = rand.nextInt(n2);
int n4 = rand.nextInt(n2);
Color color = new Color(n1,n3,n4);
JLabel image = new JLabel (new ImageIcon("space2.png"));
//JLabel image2 = new JLabel (new ImageIcon("login.png"));
JLabel userName = new JLabel("Username");
JLabel passWord = new JLabel("Password");
JTextField user = new JTextField(10);
JTextField pass = new JTextField(10);

JLabel myDog = new JLabel(new ImageIcon("space.jpeg"));


public static void main (String args[])
{
    new logIn();
}

public logIn()
{
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container c = getContentPane();
    c.setLayout(null);
    c.add(image);
    image.setBounds(0,0,1366,768);
    JLabel image2 = new JLabel (new ImageIcon("login.png"));
    c.add(image2);
    image2.setBounds(2000,2000,2000,2000);
    //c.add(image2);
    //image2.setBounds(10,10,250,250);




    //c.add(userName);
    //userName.setLayout(null);
    //userName.setBounds(50,100,100,50);

    setVisible(true);
    setSize(1366,768);

    setLayout(new BorderLayout());
    add(myDog);
    myDog.setLayout(null);
}

public void paint (Graphics g)
{
    Image a = Toolkit.getDefaultToolkit().getImage("login.png");
    g.drawImage(a,0,0,1366,768,this);
    super.paint(g);
    setVisible(true);
}

}

Answer 1

not sure what you're trying to achieve, but if you want to have multiple images (like a key image besides the password field and an avatar besides the user name, etc) you could create multiple JLabels with the different images and add them to the panel. If this is your purpose, don't override paint.

Answer 2

You need to read a few tutorials on custom painting, layouts, and gui development.

If you want to paint an image you should not load the image every repaint. You need to read that image in ahead of time. You should not be calling set visible in this method either.

Any custom painting needs to be done in paintComponent instead of paint.

Read this: http://docs.oracle.com/javase/tutorial/uiswing/painting/

It sounds like what you really want to do is create a JFrame with a panel that has a background image - and then use swing and layouts to add other components or panels with images on top of that.

So you would have a JPanel as the content pane with paintComponent overridden to only paint an image. Then build new components from there and place them using a layout manager.