import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyJDialog  extends JDialog{
public MyJDialog(){  
super(new MyFrame(),"第一个JDialog窗体",true);
  Container container=getContentPane();  
container.add(new JLabel("这是一个对话框"));  
setSize(100,100);
}
public static void main(String[] args){  
new MyJDialog();
}
}
class MyFrame extends JFrame{ public MyFrame(){
  Container container=getContentPane();  container.setLayout(null);  
JLabel jl=new JLabel("这是一个JFrame窗体");  jl.setHorizontalAlignment(SwingConstants.CENTER);  container.add(jl);  
JButton bl=new JButton("弹出对话框");  
bl.setBounds(10,10,100,21);
bl.addActionListener(new ActionListener(){   
public void actionPerformed(ActionEvent e){   
new MyJDialog().setVisible(true);
  }
  }
container.add(bl);
}
}

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyJDialog  extends JDialog{
public MyJDialog(){  
super(new MyFrame(),"第一个JDialog窗体",true);
  Container container=getContentPane();  
container.add(new JLabel("这是一个对话框"));  
setSize(100,100);
}
public static void main(String[] args){  
new MyJDialog();
}
}
class MyFrame extends JFrame{ public MyFrame(){
  Container container=getContentPane();  container.setLayout(null);  
JLabel jl=new JLabel("这是一个JFrame窗体");  jl.setHorizontalAlignment(SwingConstants.CENTER);  container.add(jl);  
JButton bl=new JButton("弹出对话框");  
bl.setBounds(10,10,100,21);
bl.addActionListener(new ActionListener(){   
public void actionPerformed(ActionEvent e){   
new MyJDialog().setVisible(true);
  }
  }
container.add(bl);
}
}