JDialog弹窗

package lesson04;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class DialogDemo extends JFrame {
    public DialogDemo() throws HeadlessException {
        this.setVisible(true);
        this.setSize(700,500);
        this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        //JFrame放东西，容器
        Container container =this.getContentPane();
        //绝对布局
        container.setLayout(null);

        //按钮
        JButton button=new JButton("点击弹出一个对话框");
        button.setBounds(30,30,200,50);
        //点击这个按钮的时候，弹出弹窗
        button.addActionListener(new ActionListener() {  //监听器
            @Override
            public void actionPerformed(ActionEvent e) {
                //弹窗
                new MyDialogDemo();

            }
        });
        container.add(button);

    }

    public static void main(String[] args) {
      new DialogDemo();


       //主窗口

    }
}
//弹窗窗口
class MyDialogDemo extends JDialog{
    public MyDialogDemo() {
        this.setVisible(true);
        this.setBounds(100,100,500,500);
//        this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        Container container=this.getContentPane();
        container.setLayout(null);

        container.add(new Label("学习java"));
    }
}