JFrame 布局 FlowLayout BorderLayout GridLayout 菜单练习 事件处理练习

Java JFrame 布局 FlowLayout BorderLayout GridLayout 菜单练习 事件处理练习

1.FlowLayout布局练习

import javax.swing.*;
import java.awt.*;

class MyJFrame01 extends JFrame {
    MyJFrame01(String s, int x, int y, int w, int h) {
        setLayout(new FlowLayout());
        setTitle(s);
        setBounds(x, y, w, h);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}


public class Flow01{
    public static void main(String args[]) {

        MyJFrame01 myJFrame = new MyJFrame01("FlowLayout Demo", 100, 100, 300, 80);

        String[] names = {"北","东","西","南","中"};
        for (String i:names) {
            myJFrame.add(new JButton(i));
        }

        myJFrame.setVisible(true);
    }
}

2.BorderLayout布局练习

import javax.swing.*;
import java.awt.*;

class MyJFrame02 extends JFrame {
    MyJFrame02(String s, int x, int y, int w, int h) {
        setLayout(new BorderLayout());
        setTitle(s);
        setBounds(x, y, w, h);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}


public class Border02{
    public static void main(String args[]) {

        MyJFrame02 myJFrame = new MyJFrame02("BorderLayout Demo", 100, 100, 160, 120);

        myJFrame.add(new JButton("北"), BorderLayout.NORTH);
        myJFrame.add(new JButton("南"), BorderLayout.SOUTH);
        myJFrame.add(new JButton("东"), BorderLayout.EAST);
        myJFrame.add(new JButton("西"), BorderLayout.WEST);
        myJFrame.add(new JButton("中"), BorderLayout.CENTER);

        myJFrame.setVisible(true);
    }
}

3.GridLayout布局练习

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

class MyJFrame03 extends JFrame {
    MyJFrame03(String s, int x, int y, int w, int h) {
        setLayout(new GridLayout(5,1));
        setTitle(s);
        setBounds(x, y, w, h);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}

public class Grid03 {
    public static void main(String[] args) {
        MyJFrame03 myJFrame = new MyJFrame03("JPanel Demo", 100, 100, 400, 400);


        JPanel panel1 = new JPanel(new FlowLayout());
        panel1.setBackground(Color.red);

        JPanel panel2 = new JPanel(new FlowLayout());
        panel2.setBackground(Color.orange);

        JPanel panel3 = new JPanel(new FlowLayout());
        panel3.setBackground(Color.yellow);

        JPanel panel4 = new JPanel(new FlowLayout());
        panel4.setBackground(Color.green);

        JPanel panel5 = new JPanel(new FlowLayout());
        panel5.setBackground(Color.blue);

        myJFrame.add(panel1);
        myJFrame.add(panel2);
        myJFrame.add(panel3);
        myJFrame.add(panel4);
        myJFrame.add(panel5);

        myJFrame.setVisible(true);
    }
}

4.菜单练习

package Exp04;

import javax.swing.*;
import java.awt.*;

class MyJFrame04 extends JFrame {
    MyJFrame04(String s, int x, int y, int w, int h) {
        setLayout(new FlowLayout());
        setTitle(s);
        setBounds(x, y, w, h);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}

public class Menu04 {
    public static void main(String args[]) {

        MyJFrame04 myJFrame = new MyJFrame04("带菜单的...", 100, 100, 230, 200);

        JMenuBar menubar = new JMenuBar();

        JMenu menu1 = new JMenu("File");
        JMenu menu2 = new JMenu("Edit");

        JMenuItem menuItem1 = new JMenuItem("open");
        JMenuItem menuItem2 = new JMenuItem("close");
        JMenuItem menuItem3 = new JMenuItem("exit");

        JMenuItem menuItem21 = new JMenuItem("copy");
        JMenu menuItem22 = new JMenu("find and replace");

        JMenuItem menuItem221 = new JMenuItem("find");
        JMenuItem menuItem222 = new JMenuItem("replace");

//        将菜单条加到窗口里
        myJFrame.setJMenuBar(menubar);

//        将菜单加到菜单条里
        menubar.add(menu1);
        menubar.add(menu2);

//        将菜单项加到菜单里
        menu1.add(menuItem1);
        menu1.add(menuItem2);
        menu1.addSeparator();// 添加分隔线
        menu1.add(menuItem3);

        menu2.add(menuItem21);
        menu2.addSeparator();// 添加分隔线
        menu2.add(menuItem22);
        menuItem22.add(menuItem221);
        menuItem22.add(menuItem222);

        myJFrame.setVisible(true);
    }
}

5.事件处理练习

点击某个按钮，在文本框中显示对应的文字。

package Exp04;

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

class MyJFrame extends JFrame {
    MyJFrame(String s, int x, int y, int w, int h) {
        setLayout(new BorderLayout());
        setTitle(s);
        setBounds(x, y, w, h);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}

public class Something05 {
    public static void main(String args[]) {

        MyJFrame myJFrame = new MyJFrame("我...", 100, 100, 160, 150);

// 创建上半部分panel1玻璃窗，存放文本域
        Panel panel1 = new Panel(new FlowLayout());
        JTextArea textArea = new JTextArea(1, 10);
        panel1.add(new JScrollPane(textArea));

// 创建上半部分panel1玻璃窗，存放五个按钮
        Panel panel2 = new Panel(new BorderLayout());
//分别独立创建 东西南北中 五个按钮，以便后续监听使用
        String[] name = {"北","南","东","西","中"};
        JButton[] button = new JButton[5];

        JButton button_north = new JButton("北");
        panel2.add(button_north, BorderLayout.NORTH);
        JButton button_south = new JButton("南");
        panel2.add(button_south, BorderLayout.SOUTH);
        JButton button_east = new JButton("东");
        panel2.add(button_east, BorderLayout.EAST);
        JButton button_west = new JButton("西");
        panel2.add(button_west, BorderLayout.WEST);
        JButton button_center = new JButton("中");
        panel2.add(button_center, BorderLayout.CENTER);

        JButtonHandler listener = new JButtonHandler();
//创建监听事件，listener实例，以及连接文本域
        listener.setJTextArea(textArea);
//监听各按钮
        button_north.addActionListener(listener);
        button_south.addActionListener(listener);
        button_east.addActionListener(listener);
        button_west.addActionListener(listener);
        button_center.addActionListener(listener);

//将两个玻璃窗放入容器窗格，构造完成
        myJFrame.add(panel1, BorderLayout.NORTH);
        myJFrame.add(panel2, BorderLayout.CENTER);
        myJFrame.setVisible(true);
    }
}

class JButtonHandler implements ActionListener {
    JTextArea textshow;

    public void setJTextArea(JTextArea area) {
        textshow = area;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
//e.getActionCommand()得到button按钮上的字符串
        textshow.setText("");
        switch (e.getActionCommand()) {
            case "北":
                textshow.append("北");
                break;
            case "南":
                textshow.append("南");
                break;
            case "东":
                textshow.append("东");
                break;
            case "西":
                textshow.append("西");
                break;
            case "中":
                textshow.append("中");
                break;
            default:
                textshow.append("请重新点击");
        }
    }
}