如何在java的Swing GUI中将图像设置为Frame的背景？

Question

I have created one GUI using Swing of Java. I have to now set one sample.jpeg image as a background to the frame on which I have put my components.How to do that ?

Answer 1

There is no concept of a "background image" in a JPanel , so one would have to write their own way to implement such a feature.

One way to achieve this would be to override the paintComponent method to draw a background image on each time the JPanel is refreshed.

For example, one would subclass a JPanel , and add a field to hold the background image, and override the paintComponent method:

public class JPanelWithBackground extends JPanel {

  private Image backgroundImage;

  // Some code to initialize the background image.
  // Here, we use the constructor to load the image. This
  // can vary depending on the use case of the panel.
  public JPanelWithBackground(String fileName) throws IOException {
    backgroundImage = ImageIO.read(new File(fileName));
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);

    // Draw the background image.
    g.drawImage(backgroundImage, 0, 0, this);
  }
}

(Above code has not been tested.)

The following code could be used to add the JPanelWithBackground into a JFrame :

JFrame f = new JFrame();
f.getContentPane().add(new JPanelWithBackground("sample.jpeg"));

In this example, the ImageIO.read(File) method was used to read in the external JPEG file.

Answer 2

This is easily done by replacing the frame's content pane with a JPanel which draws your image:

try {
    final Image backgroundImage = javax.imageio.ImageIO.read(new File(...));
    setContentPane(new JPanel(new BorderLayout()) {
        @Override public void paintComponent(Graphics g) {
            g.drawImage(backgroundImage, 0, 0, null);
        }
    });
} catch (IOException e) {
    throw new RuntimeException(e);
}

This example also sets the panel's layout to BorderLayout to match the default content pane layout.

(If you have any trouble seeing the image, you might need to call setOpaque(false) on some other components so that you can see through to the background.)

Answer 3

背景面板条目根据您的要求显示了几种不同的方式。

Answer 4

You can either make a subclass of the component

http://www.jguru.com/faq/view.jsp?EID=9691

Or fiddle with wrappers

http://www.java-tips.org/java-se-tips/javax.swing/wrap-a-swing-jcomponent-in-a-background-image.html

Answer 5

Here is another quick approach without using additional panel.

JFrame f = new JFrame("stackoverflow") { 
  private Image backgroundImage = ImageIO.read(new File("background.jpg"));
  public void paint( Graphics g ) { 
    super.paint(g);
    g.drawImage(backgroundImage, 0, 0, null);
  }
};

Answer 6

if you are using netbeans you can add a jlabel to the frame and through properties change its icon to your image and remove the text. then move the jlabel to the bottom of the Jframe or any content pane through navigator

Answer 7

Perhaps the easiest way would be to add an image, scale it, and set it to the JFrame/JPanel (in my case JPanel) but remember to "add" it to the container only after you've added the other children components.

    ImageIcon background=new ImageIcon("D:\\FeedbackSystem\\src\\images\\background.jpg");
    Image img=background.getImage();
    Image temp=img.getScaledInstance(500,600,Image.SCALE_SMOOTH);
    background=new ImageIcon(temp);
    JLabel back=new JLabel(background);
    back.setLayout(null);
    back.setBounds(0,0,500,600);

Answer 8

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class BackgroundImageJFrame extends JFrame
{
  JButton b1;
  JLabel l1;
public BackgroundImageJFrame()
{
setTitle("Background Color for JFrame");
setSize(400,400);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
/*
 One way
-----------------*/
setLayout(new BorderLayout());
JLabel background=new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads\\colorful design.png"));
add(background);
background.setLayout(new FlowLayout());
l1=new JLabel("Here is a button");
b1=new JButton("I am a button");
background.add(l1);
background.add(b1);

// Another way
setLayout(new BorderLayout());
setContentPane(new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads  \\colorful design.png")));
setLayout(new FlowLayout());
l1=new JLabel("Here is a button");
b1=new JButton("I am a button");
add(l1);
add(b1);
// Just for refresh :) Not optional!
  setSize(399,399);
   setSize(400,400);
   }
   public static void main(String args[])
  {
   new BackgroundImageJFrame();
 }
 }