java中透明窗口 再也不用局限于矩形窗口了

mport java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*; public class test { ImageIcon imageIcon =new ImageIcon("透明旋转枫.gif");//images这个文件 ImageIcon imagebutton=new ImageIcon("button.png"); JLabel j2=new JLabel(); public test(){ final JFrame f= new JFrame(); f.setBounds(0,00,400,300); f.setDefaultCloseOperation(3); f.setUndecorated(true); com.sun.awt.AWTUtilities.setWindowOpaque(f,false);//设置窗体透明 JPanel p=new JPanel(){ public void paintComponent(Graphics g){//重写paintComponent super.paintComponent(g);//继承的绘制组件方法 Graphics2D gg=(Graphics2D)g; if(imageIcon !=null){//绘制背景 gg.drawImage(imageIcon.getImage(),0,0,f.getWidth(),f.getHeight(),f); } } }; p.setLayout(null);//空布局 任意摆放 与下面的b1.setBounds(280,80,60,25);呼应 JButton b1=new JButton("exit",imagebutton); b1.addActionListener(new ActionListener(){ public void actionPerformed (ActionEvent e){ System.exit(0); } });