Java Gui 事件监听
事件监听
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当某个事情发生的时候，干什么？
package com.xiao.lessson02; 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(); //因为，addActionListener()需要一个ActionListener,所以我们需要构造一个ActionListener MyActionListener myActionListener = new MyActionListener(); frame.add(button,BorderLayout.CENTER); frame.pack(); windowClose(frame); frame.setVisible(true); } private static void windowClose(Frame frame){ frame.addWindowListener((new WindowAdapter() { @Override public void windowClosing(WindowEvent e) { System.exit(0); } })); } static class MyActionListener implements ActionListener{ @Override public void actionPerformed(ActionEvent e) { System.out.println("aaa"); } } } -
多个按钮共享一个事件
package com.xiao.lessson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestActionTwo {
public static void main(String[] args) {
//两个按钮，实现同一个监听
//开始 停止
Frame frame = new Frame("开始-停止");
Button button1 = new Button("start");
Button button2 = new Button("stop");
//可以显示的定义触发会返回的命令，如果不显示定义，则会走默认的值！
//可以多个按钮只写一个监听类
button2.setActionCommand("button2-stop");
MyMonitor myMonitor = new MyMonitor();
button1.addActionListener(myMonitor);
button2.addActionListener(myMonitor);
frame.add(button1,BorderLayout.NORTH);
frame.add(button2,BorderLayout.SOUTH);
frame.pack();
frame.setVisible(true);
}
}
class MyMonitor implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
//e.getActionCommand() 获得按钮的信息
System.out.println("按钮被点击了：msg"+e.getActionCommand());
}
}
Java GUI 事件监听
Java-GUI事件监听机制
package com.xiao.lesson03;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;
//鼠标监听事件
public class TestMouseListener {
public static void main(String[] args) {
new MyFrame("画图");
}
}
//自己的类
class MyFrame extends Frame{
//画画需要画笔，需要监听鼠标当前的位置，需要集合来存储这个点
ArrayList points;
public MyFrame(String title){
super(title);
setBounds(200,200,400,300);
points = new ArrayList<>();
setVisible(true);
//鼠标监听器，正对这个窗口
this.addMouseListener(new MyMouseListener());
}
@Override
public void paint(Graphics g) {
//画画，监听鼠标的事件
Iterator integer = points.iterator();
while (integer.hasNext()){
Point point = (Point) integer.next();
g.setColor(Color.BLUE);
g.fillOval(point.x,point.y,10,10);
}
}
//添加一个点到界面上
public void addPaint(Point point){
points.add(point);
}
//适配器模式
private class MyMouseListener extends MouseAdapter{
//鼠标 按下，弹起，
@Override
public void mousePressed(MouseEvent e) {
MyFrame frame = (MyFrame) e.getSource();
//这个我们点击的时候，就会在界面上产生一个点！画
//这个点就是鼠标的点
frame.addPaint(new Point(e.getX(),e.getY()));
//每次点击鼠标都需要重新画一遍
frame.repaint();//刷新
}
}
}
窗口监听
package com.xiao.lesson03;
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.BLUE);
setBounds(100,100,200,200);
setVisible(true);
//addWindowListener(new MyWindowListener());
//匿名内部类
new WindowAdapter(){
@Override
public void windowClosing(WindowEvent e) {
System.out.println("你点击了送完");
System.exit(0);
}
};
}
// class MyWindowListener extends WindowAdapter{
// @Override
// public void windowClosing(WindowEvent e) {
// setVisible(false); //隐藏窗口，
// System.exit(0); //正常退出
// }
// }
}
简易计算器，组合+内部类回顾复习！
oop原则：组合，大于继承
未做优化
class A extends B{
}
class A{
public B b;
}
//3 个文本框
TextField num1 = new TextField(10);
TextField num2 = new TextField(10);
TextField num3 = new TextField(10);
//1 个按钮
Button button = new Button("=");
//1个标签
Label label = new Label("+");
//布局
setLayout(new FlowLayout());
add(num1);
add(label);
add(num2);
add(button);
修改后的面向对象
package com.xiao.lessson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestCalc {
public static void main(String[] args) {
new Calculator().loadFrame();
}
}
//计算器类
class Calculator extends Frame {
//属性
TextField num1, num2, num3;
//方法
public void loadFrame() {
//3 个文本框
num1 = new TextField(10);
num2 = new TextField(10);
num3 = new TextField(10);
Label label = new Label("+");
Button button = new Button("=");
button.addActionListener(new MyCalculatorListener(this));
//布局
setLayout(new FlowLayout());
add(num1);
add(label);
add(num2);
add(button);
add(num3);
pack();
setVisible(true);
}
}
//监听器类
class MyCalculatorListener implements ActionListener{
//获取计算器这个对象，在一个类中组合另外一个类；
Calculator calculator = null;
public MyCalculatorListener(Calculator calculator) {
this.calculator = calculator;
}
@Override
public void actionPerformed(ActionEvent e) {
//获得加数和被加数
//将这个值 + 法运算后，放到第三个框
// 清除前两个框
int n1 = Integer.parseInt(calculator.num1.getText());
int n2 = Integer.parseInt(calculator.num2.getText());
calculator.num3.setText(""+(n1+n2));
calculator.num1.setText("");
calculator.num2.setText("");
}
}
内部类
更好的包装
package com.xiao.lessson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestCalc {
public static void main(String[] args) {
new Calculator().loadFrame();
}
}
//计算器类
class Calculator extends Frame {
//属性
TextField num1, num2, num3;
//方法
public void loadFrame() {
//3 个文本框
num1 = new TextField(10);
num2 = new TextField(10);
num3 = new TextField(10);
Label label = new Label("+");
Button button = new Button("=");
button.addActionListener(new MyCalculatorListener());
//布局
setLayout(new FlowLayout());
add(num1);
add(label);
add(num2);
add(button);
add(num3);
pack();
setVisible(true);
}
//监听器类
//内部类最大的好处，就是可以畅通无阻的访问外部的属性和方法！
private class MyCalculatorListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
//获得加数和被加数
//将这个值 + 法运算后，放到第三个框
// 清除前两个框
int n1 = Integer.parseInt(num1.getText());
int n2 = Integer.parseInt(num2.getText());
num3.setText("" + (n1 + n2));
num1.setText("");
num2.setText("");
}
}
}
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