1、简介

GUI的核心技术：Swing、 AWT
1、外观不太美观，组件数量偏少
2、运行需要JRE环境

为什么我们要学习？

组件(JTable,JList等)很多都是MVC的经典示范，学习也可以了解mvc架构。
工作时,也有可能遇见需要维护N年前awt/swing写的软件（可能性极小）
可以写一些自己使用的软件

2、AWT

2.1 AWT介绍

AWT(Abstract Window Toolkit)，中文译为抽象窗口工具包。包括了很多类和接口，用于Java Application的GUI（Graphics User Interface 图形用户界面）编程。
GUI的各种元素（如：窗口，按钮，文本框等）由Java类来实现。
使用AWT所涉及的类一般在Java.AWT包及其子包中。
Container和Component是AWT中的两个核心类。

在这里插入图片描述

2.2 组件和容器

//GUI的第一个界面
public class TestFrame {
    public static void main(String[] args) {

        //这里只是在内存里面创建了一个窗口对象 还不能真正显示出来然我们看到
        Frame frame = new Frame("My First Java GUI");

        frame.setVisible(true);
        frame.setSize(400,400);

        frame.setBackground(new Color(229, 106, 106));
        //设置窗体出现时的位置，如果不设置则默认在左上角(0,0)位置显示
        frame.setLocation(200,200);
        //窗口大小固定
        frame.setResizable(false);


    }
}

此时是无法通过窗口的叉来关闭窗口的，需要手动关闭程序运行

我们进行封装，一次new出多个窗口

public class TestFrame2 {
    public static void main(String[] args) {
        MyFrame myFrame1 = new MyFrame(100, 100, 200, 200, Color.blue);
        MyFrame myFrame2 = new MyFrame(300, 100, 200, 200, Color.yellow);
        MyFrame myFrame3 = new MyFrame(100, 300, 200, 200, Color.red);
        MyFrame myFrame4 = new MyFrame(300, 300, 200, 200, Color.green);
    }
}

class MyFrame extends Frame{
    //可能存在多个窗口，需要一个计数器
    static int id=0;

    public MyFrame(int x,int y,int w,int h,Color color){
        super("MyFrame "+(++id));
        setBounds(x,y,w,h);
        setVisible(true);
        setBackground(color);
    }
}

在这里插入图片描述

2.3 Panel

//Panel可以看成是一个空间，但是不能单独存在
public class TestPanel {
    public static void main(String[] args) {
        Frame frame=new Frame();

        Panel panel = new Panel();
        //设置布局
        frame.setLayout(null);

        frame.setBounds(300,300,500,500);
        frame.setBackground(Color.pink);
        frame.setVisible(true);

        //panel设置坐标，相对于frame
        panel.setBounds(50,50,100,100);
        panel.setBackground(new Color(78, 210, 159));

        frame.add(panel);
        frame.setVisible(true);

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

在这里插入图片描述

2.4 布局管理器

流式布局
东南西北中
表格布局

2.4.1 流式布局

public class TestFlowLayout {
    public static void main(String[] args) {
        Frame frame = new Frame();

        Button button1 = new Button("button1");
        Button button2 = new Button("button2");
        Button button3 = new Button("button3");

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

        frame.setSize(200,200);
        frame.setVisible(true);

        frame.add(button1);
        frame.add(button2);
        frame.add(button3);
    }
}

2.4.2 东南西北中

public class TestBorderLayout {
    public static void main(String[] args) {
        Frame frame = new Frame("TestBorderLayout");

        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.setSize(300,300);
        frame.setVisible(true);

        frame.addWindowListener(new WindowAdapter(){
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

2.4.3 表格布局

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

        Frame frame = new Frame("TestGridLayout");

        Button button1 = new Button("button1");
        Button button2 = new Button("button2");
        Button button3 = new Button("button3");
        Button button4 = new Button("button4");
        Button button5 = new Button("button5");
        Button button6 = new Button("button6");

        frame.setLayout(new GridLayout(3,2));

        frame.add(button1);
        frame.add(button2);
        frame.add(button3);
        frame.add(button4);
        frame.add(button5);
        frame.add(button6);

        frame.setSize(200,200);
        frame.setVisible(true);
    }
}

现在学会了这三个布局和面板，检验一下，完成这个案例
在这里插入图片描述

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

public class Test {
    public static void main(String[] args) {
        Frame frame=new Frame();
        frame.setVisible(true);
        frame.setSize(400,400);
        frame.setBackground(Color.pink);
        frame.setLocation(300,400);

        frame.setLayout(new GridLayout(2,1));

        //4个面板
        Panel p1 = new Panel(new BorderLayout());
        Panel p2 = new Panel(new GridLayout(2, 1));
        Panel p3 = new Panel(new BorderLayout());
        Panel p4= new Panel(new GridLayout(2, 2));

        p1.add(new Button("East-1"),BorderLayout.EAST);
        p1.add(new Button("West-1"),BorderLayout.WEST);
        p2.add(new Button("p2-Button1"));
        p2.add(new Button("p2-Button2"));
        p1.add(p2,BorderLayout.CENTER);

        p3.add(new Button("East-2"),BorderLayout.EAST);
        p3.add(new Button("West-2"),BorderLayout.WEST);
        p4.add(new Button("p4-Button1"));
        p4.add(new Button("p4-Button2"));
        p4.add(new Button("p4-Button3"));
        p4.add(new Button("p4-Button4"));
        p3.add(p4,BorderLayout.CENTER);

        frame.add(p1);
        frame.add(p3);

        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }

}

在这里插入图片描述

2.5 事件监听

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

public class TestActionEvent {
    public static void main(String[] args) {
        //按下按钮，触发一些事件
        Frame frame = new Frame();
        Button button = new Button("Button");

        //addActionListener() 需要一个ActionListener，所以我们需要构造一个ActionListener
        button.addActionListener(new MyActionListener());

        frame.add(button,BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);

        //关闭窗口
        windowClose(frame);
    }

    //关闭窗体的事件
    private static void windowClose(Frame frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

class MyActionListener implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("Button");
    }
}

可以看到当我们点击Button的时候，会触发事件，这个事件正是我们重写的actionPerformed方法中的内容
在这里插入图片描述

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

public class TestActionEvent2 {
    public static void main(String[] args) {
 
        Frame frame = new Frame();
        Button button1 = new Button("start");
        Button button2 = new Button("stop");

        button1.setActionCommand("开始");
        button2.setActionCommand("停止");


        button1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("msg: "+e.getActionCommand());
            }
        });
        button2.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("msg: "+e.getActionCommand());
            }
        });

        frame.setLayout(new GridLayout(2,1));
        frame.add(button1);
        frame.add(button2);
        frame.pack();
        frame.setVisible(true);

        //关闭窗口
        windowClose(frame);
    }


    //关闭窗体的事件
    private static void windowClose(Frame frame) {
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

在这里插入图片描述

这里也可以写一个实现类来实现ActionListener，两个按钮实现同一个监听

2.6 TextField事件监听

package com.demo2;

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

public class TestTextField {
    public static void main(String[] args) {
        new MyFrame();
    }
}
class MyFrame extends Frame{
    public MyFrame(){
        TextField textField = new TextField();
        add(textField);

        //监听这个文本框输入的文字
        //按下enter，就会触发这个事件
        textField.addActionListener(new MyActionListener2());
        
        //设置替换编码
        textField.setEchoChar('*');

        setVisible(true);
        pack();

    }
}

class MyActionListener2 implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent e) {
        //获得一些资源 返回一个对象
        TextField field = (TextField) e.getSource();
        //获取输入框的文本
        System.out.println(field.getText());
        //设置为空字符串
        field.setText("");
    }
}

2.7 简易计数器

初始版本

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

public class TestCalc {
    public static void main(String[] args) {
        new Calculator();

    }
}

//计算器类
class Calculator extends Frame{
    public Calculator(){
        TextField num1 = new TextField(10);
        TextField num2 = new TextField(10);
        TextField sum = new TextField(20);

        Button button = new Button("Calc");

        button.addActionListener(new MyCalculatorListener(num1,num2,sum));

        Label label1 = new Label("+");
        Label label2 = new Label("=");

        setLayout(new FlowLayout());
        add(num1);
        add(label1);
        add(num2);
        add(label2);
        add(sum);
        add(button);

        pack();
        setVisible(true);
        exit();
    }

    private void exit(){
        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

//监听器类
class MyCalculatorListener implements ActionListener{
    private TextField num1,num2,sum;

    public MyCalculatorListener(TextField num1,TextField num2,TextField sum){
        this.num1=num1;
        this.num2=num2;
        this.sum=sum;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        int n1 = Integer.parseInt(num1.getText());
        int n2 = Integer.parseInt(num2.getText());

        int n3=n1+n2;
        sum.setText(String.valueOf(n3));
        num1.setText("");
        num2.setText("");
    }
}

改造为面向对象

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

public class TestCalc {
    public static void main(String[] args) {
        new Calculator().loadFrame();

    }
}

//计算器类
class Calculator extends Frame {
    TextField num1, num2, sum;

    public void loadFrame() {
        num1 = new TextField(10);
        num2 = new TextField(10);
        sum = new TextField(20);
        Button button = new Button("Calc");
        Label label1 = new Label("+");
        Label label2 = new Label("=");

        button.addActionListener(new MyCalculatorListener(this));

        setLayout(new FlowLayout());
        add(num1);
        add(label1);
        add(num2);
        add(label2);
        add(sum);
        add(button);

        pack();
        setVisible(true);
        exit();
    }


    private void exit() {
        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

//监听器类
class MyCalculatorListener implements ActionListener {
    //获取计算机这个对象，在一个类中组合另一个类
    Calculator calculator = null;

    public MyCalculatorListener(Calculator calculator) {
        this.calculator = calculator;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        int n1 = Integer.parseInt(calculator.num1.getText());
        int n2 = Integer.parseInt(calculator.num2.getText());
        calculator.sum.setText(String.valueOf(n1 + n2));
        calculator.num1.setText("");
        calculator.num2.setText("");
    }
}

改造为内部类

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

public class TestCalc {
    public static void main(String[] args) {
        new Calculator().loadFrame();

    }
}

//计算器类
class Calculator extends Frame {
    TextField num1, num2, sum;

    public void loadFrame() {
        num1 = new TextField(10);
        num2 = new TextField(10);
        sum = new TextField(20);
        Button button = new Button("Calc");
        Label label1 = new Label("+");
        Label label2 = new Label("=");

        button.addActionListener(new MyCalculatorListener());

        setLayout(new FlowLayout());
        add(num1);
        add(label1);
        add(num2);
        add(label2);
        add(sum);
        add(button);

        pack();
        setVisible(true);
        exit();
    }


    private void exit() {
        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }

    //监听器类
	//内部类最大的好长就是可以畅通无阻的访问外部类的属性和方法
    private class MyCalculatorListener implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            int n1 = Integer.parseInt(num1.getText());
            int n2 = Integer.parseInt(num2.getText());
            sum.setText(String.valueOf(n1 + n2));
            num1.setText("");
            num2.setText("");
        }
    }
}

2.8 画笔

每个Component都有一个paint（Graphics g）用于实现绘图目的，每次重画该Component时都自动调用paint方法。

import java.awt.*;

public class TestPaint {
    public static void main(String[] args) {
    //在main()方法里面并没有显示调用paint(Graphics g)方法
        new MyPaint().loadFrame();
    }
}

class MyPaint extends Frame {

    public void loadFrame(){
        setBounds(200,200,600,400);
        setVisible(true);
    }
    @Override
    public void paint(Graphics graphics){
        graphics.setColor(Color.red);
        graphics.drawOval(100,100, 100,100);
        graphics.fillOval(200,100,100,100);

        graphics.setColor(Color.BLUE);
        graphics.fillRect(100,200,100,100);

        // 养成习惯，画笔用完 还原为最初的颜色
        graphics.setColor(Color.BLACK);
        
    }
}

2.9 鼠标监听事件

抽象类java.awt.event.MouseAdapter实现了MouseListener接口，可以使用其子类作为MouseEvent的监听器，只要重写其相应的方法即可。

import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import java.util.Iterator;

public class TestMouseListener {
    public static void main(String[] args) {
        new MyFrame("画图");
    }
}

class MyFrame extends Frame {
    //存储坐标
    private ArrayList points;
    //画画需要画笔，需要监听鼠标当前位置，需要集合来存储这个点

    public MyFrame(String title){
        super(title);
        setVisible(true);
        setBounds(200,200,400,300);
        //存储坐标
        points=new ArrayList<>();


        //鼠标监听器，对这个窗口
        addMouseListener(new MyMouseListener());
    }

    @Override
    public void paint(Graphics g) {
       //画画，监听鼠标的事件
        Iterator iterator = points.iterator();
        while(iterator.hasNext()){
            Point point = (Point) iterator.next();
            g.setColor(Color.BLUE);
            g.fillOval(point.x,point.y,10,10);
        }
    }

    public void addPaint(Point point){
        points.add(point);
    }

    private class MyMouseListener extends MouseAdapter {

        //鼠标按压
        @Override
        public void mousePressed(MouseEvent e) {
            //获取被监听的对象
            MyFrame myFrame =(MyFrame) e.getSource();
            //鼠标的坐标
           myFrame.addPaint( new Point(e.getX(),e.getY()));

           //每次点击鼠标都需要重新画一次
            myFrame.repaint();//刷新
        }
    }
}

2.10 窗口监听

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

public class TestWindow {
    public static void main(String[] args) {
        new WindowFrame();
    }
}
class WindowFrame extends Frame {
    public WindowFrame(){
        setBackground(Color.pink);
        setBounds(100,100,200,200);
        setVisible(true);
        //addWindowListener(new MyWindowListener());
        //使用内部类
        addWindowListener(new WindowAdapter() {
            //关闭窗口
            @Override
            public void windowClosing(WindowEvent e) {
                System.out.println("退出");
                System.exit(0);
            }

            //激活窗口
            @Override
            public void windowActivated(WindowEvent e) {
                WindowFrame frame =(WindowFrame) e.getSource();
                frame.setTitle("被激活");
                System.out.println("windowActivated");
            }
        });
    }


    class MyWindowListener extends WindowAdapter{
        @Override
        public void windowClosing(WindowEvent e) {
            //隐藏窗口
            setVisible(false);
            System.exit(0);//正常退出
        }
    }
}

2.11 键盘监听

import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

public class TestKeyListener {
    public static void main(String[] args) {
        new KeyFrame();

    }
}

class KeyFrame extends Frame {
    public KeyFrame(){

        setBounds(100,100,200,200);
        setVisible(true);

        addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
            //KeyEvent.VK_UP表示取得up键的虚拟码
           //键盘中的每一个键都对应有一个虚拟码这些虚拟码在KeyEvent类里面都被定义为静态常量
           //使用“类名.静态常量名”的形式访问得到这些静态常量
                System.out.println(e.getKeyCode());
                //获取键盘的码
              if ( e.getKeyCode()==KeyEvent.VK_UP){
                  System.out.println("按下了上键");
              }
            }
        });
        
    }
}