GUI初阶：监听事件（案例：简易画图软件）

GUI初阶：监听事件（案例：简易画图软件）

一、鼠标监听

addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
        }
    });

二、窗口监听

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

三、键盘监听

addKeyListener(new KeyAdapter() {
            public void keyPressed(KeyEvent e) {
                int Keycode = e.getKeyCode();//获取键盘输入的值
                if(Keycode == KeyEvent.VK_xxx);{
                    执行语句
                }
            }
        });

简易画图软件源代码：

/*
              ————Gui初阶：监听事件（案例：简易画图软件）————

一、鼠标监听
addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
        }
    });


二、窗口监听
    addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    });

三、键盘监听
addKeyListener(new KeyAdapter() {
            public void keyPressed(KeyEvent e) {
                int Keycode = e.getKeyCode();//获取键盘输入的值
                if(Keycode == KeyEvent.VK_xxx);{
                    执行语句
                }
            }
        });

 */
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Iterator;


public class Paints {
    public static void main(String[] args) {
        new ListenerFrame("画图工具");
    }
}

class ListenerFrame extends Frame{

    ArrayList points;

    //程序建立方法
    public ListenerFrame(String name){
        super(name);//设定窗口名
    setBounds(100,100,400,500);
    setVisible(true);
    //建立点仓库
    points = new ArrayList<>();

    //添加鼠标事件监听器
    addMouseListener(new MouseAdapter() {
        @Override
        public void mousePressed(MouseEvent e) {
            addPaint(new Point(e.getX(),e.getY()));
            repaint();
        }
    });
    //添加键盘事件监听器
        addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                int Keycode = e.getKeyCode();
                if(Keycode == KeyEvent.VK_ENTER);{
                    System.exit(0);
                }
            }
        });
    //添加窗口监听事件
    addWindowListener(new WindowAdapter() {

        public void windowOpened(WindowEvent e) {
            System.out.println("欢迎光临");
        }

        public void windowClosing(WindowEvent e) {
            System.out.println("欢迎下次使用菜逼画图工具");
            System.exit(0);
        }
    });
    }
    //建立画笔工具
    @Override
    public void paint(Graphics g) {
        Iterator iterator = points.iterator();
        while (iterator.hasNext()){
            Point point = (Point) iterator.next();
            g.setColor(Color.green);
            g.fillOval(point.x,point.y,10,10);
        }
    }
    //添加点到界面上
    public void addPaint(Point point){
        points.add(point);
    }
}