学习面panel和三种布局

1、面板panel

package Java2;

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

/**
 * 学习面板 Panel
 * Panel：可以看做是一个空间，但是不能单独存在
 */
public class demo03 {
    public static void main(String[] args) {
        Frame frame = new Frame();
        Panel panel = new Panel();
        //设置布局
        frame.setLayout(null);

        //坐标
        frame.setBounds(300,300,500,500);
        frame.setBackground(new Color(50, 133, 21));

        //panel设置坐标，相对于frame
        panel.setBounds(50,50,400,400);
        panel.setBackground(new Color(193,15,50));

        //把面板添加到frame里面去
        frame.add(panel);
        frame.setVisible(true);

        //监听事件，监听窗口关闭事件 ，System.exit(0)
        //适配器模式
        frame.addWindowListener(new WindowAdapter() {
            //窗口点击关闭的时候需要做的事情
            @Override
            public void windowClosing(WindowEvent e) {
                //结束程序
                System.exit(0);
            }
    });
    }
}

2、布局：有三种

①流式布局；

②东西南北中布局；

③表格布局；

package Java2;

import java.awt.*;

public class demo04 {
    public static void main1(String[] args) {
        //流式布局 ：从左到右，像水一样
        Frame frame = new Frame();
        //组件-按钮
        Button button1 = new Button("button1");
        Button button2 = new Button("button2");
        Button button3 = new Button("button3");

        //设置为流式布局
       // frame.setLayout(new FlowLayout());
        frame.setLayout(new FlowLayout(FlowLayout.LEFT));

        //把按钮添加上去
        frame.add(button1);
        frame.add(button2);
        frame.add(button3);
        frame.setSize(200,200);
        frame.setVisible(true);

    }

    public static void main2(String[] args) {
        Frame frame = new Frame("BorderLayout");
        //东西南北中布局
        Button east = new Button("East");
        Button west = new Button("West");
        Button south = new Button("South");
        Button north = new Button("North");
        Button center = new Button("Center");

        frame.add(east,BorderLayout.EAST);
        frame.add(west,BorderLayout.WEST);
        frame.add(south,BorderLayout.SOUTH);
        frame.add(north,BorderLayout.NORTH);
        frame.add(center,BorderLayout.CENTER);
        frame.setVisible(true);
        frame.setSize(300,300);
    }

    public static void main(String[] args) {
        Frame frame = new Frame("GridLayout");
        //表格布局
        Button btn1 = new Button("btn1");
        Button btn2 = new Button("btn2");
        Button btn3 = new Button("btn3");
        Button btn4 = new Button("btn4");
        Button btn5 = new Button("btn5");
        Button btn6 = new Button("btn6");

        frame.setLayout(new GridLayout(3,2));
        frame.add(btn1);
        frame.add(btn2);
        frame.add(btn3);
        frame.add(btn4);
        frame.add(btn5);
        frame.add(btn6);
        frame.pack();//java函数 ：它会自动选择最合适的布局
        frame.setVisible(true);

    }
}

三种结果为：