swing界面的简单使用

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class x3 extends JFrame implements ActionListener{

          JButton btn,btn1,btn2;

          JPanel pan;
public x3(){
super("身份选择窗口");
btn=new JButton("管理员");
btn1=new JButton("用户");
btn2=new JButton("退出");
JLabel label=new JLabel("请选择你的身份");
pan=new JPanel();
pan.setLayout(null);//一定要不然没用
Container cont=getContentPane();
btn.setBounds(150, 100, 100,60);
btn1.setBounds(150, 200, 100,60);
btn2.setBounds(150, 300, 100,60);
label.setBounds(150,30,100,60);
pan.add(label);
pan.add(btn);
pan.add(btn1);
pan.add(btn2);
btn.addActionListener(this);
btn1.addActionListener(this);
cont.add(pan);
setSize(500, 500);
setVisible(true);
}

         
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==btn){
setVisible(false);
x5 n=new x5();//运行同一个包里的x5.java文件内容
}
if(e.getSource()==btn1){
setVisible(false);
x1 n=new x1();
}
}
  public static void main(String args[]){
           /*
Object[] options={"ok","CANCEL"};
           
JOptionPane.showOptionDialog(null, "HELLO", "Waring", JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE, null, options, options[0]);
           */
           
/*JOptionPane.showMessageDialog(null, "woaini","sjdfi",JOptionPane.INFORMATION_MESSAGE);*/
           /*String no;
           no=JOptionPane.showInputDialog("输入一个数字");
           System.out.println(no);*/
           
new x3();
           }
}