15.JDialog弹窗

JDialog，用来被弹出，默认就有关闭事件

package com.gui.lesson4;

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

//主窗口
public class DialogDemo extends JFrame {

    public DialogDemo() {
        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，弹出一个弹窗
        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();
    }
}

//弹窗的窗口
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.add(new JLabel("Hello,Java!",SwingConstants.CENTER));
    }
}