JFrame中设置背景图片

首先在JFrame中添加一个JPanel，重写JPanel方法package com.project.swing;import java.awt.Graphics;import java.awt.Image;import javax.swing.ImageIcon;import javax.swing.JPanel;public class BackgroundJPanel extends JPanel{Image img;// BackgroundJPanel backPanel;public BackgroundJPanel(Image img){this.img=img;this.setOpaque(true);}public void paintComponent(Graphics g){super.paintComponent(g);g.drawImage(img,0,0,this.getWidth(),this.getHeight(),this);}}我在测试类test.class添加代码BackgroundJPanel backgroundJPanel=new BackgroundJPanel(new ImageIcon(test.class.getResource("first.jpg")).getImage());//这里的test是测试类名，first.jpg

//自行添加到test.class所在的包内
backgroundJPanel.setBounds(0,0,1000,618);//设置JPanel的位置以及height与Width；

最后添加到JFrame中this.add(backgroundJPanel);