GUI编程(AWT_02)
GUI编程
4.事件监听
事件监听：当某个事情发生的时候，干什么？
package com.deng.lesson02;
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 addAcitonListener()需要一个ActionListener，所以我们需要构造一个ActionListener
MyActionListener myActionListener = new MyActionListener();
button.addActionListener(myActionListener);
frame.add(button,BorderLayout.CENTER);
frame.pack();//自适应
windowClose(frame);
frame.setVisible(true);
}
//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);
}
});
}
}
//事件监听
class MyActionListener implements ActionListener{
//快捷键 Ctrl+i
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("aaa");
}
}
多个按钮共享一个事件
package com.deng.lesson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestActionTwo {
public static void main(String[] args) {
//两个Annie，实现同一个监听
//开始 停止
Frame frame = new Frame("开始-停止");
Button button1 = new Button();
Button button2 = new Button();
//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());
if(e.getActionCommand().equals("start")){
}
}
}
5.输入框TextField监听
package com.deng.lesson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestText01 {
public static void main(String[] args) {
//启动！
new MyFrame();
}
}
class MyFrame extends Frame {
public MyFrame() {
TextField textField = new TextField(); //TextField 单行文本
add(textField);
//监听这个文本框输入的文字
MyActionListener2 myActionListener2 = new MyActionListener2();
//按下Enter就会触发这个输入框的事件
textField.addActionListener(myActionListener2);
//设置替换编码
textField.setEchoChar('*');
setVisible(true);
pack();
}
}
class MyActionListener2 implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
TextField field = (TextField) e.getSource();//获得一些资源,返回的一个对象
System.out.println(field.getText());//获得输入框中的文本
field.setText("");//null对象 ""字符串 回车清空文本框
}
}
6.简易计算器
组合+内部类回顾复习
6.1代码
package com.deng.lesson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//简易计算器
public class TestCalc {
public static void main(String[] args) {
new Calculator();
}
}
//计算器类
class Calculator extends Frame {
public Calculator() {
//3个文本框
TextField num1 = new TextField(10);//字符数
TextField num2 = new TextField(10);//字符数
TextField num3 = new TextField(20);//字符数
//1个按钮
Button button = new Button("=");
button.addActionListener(new MyCalListener(num1, num2, num3));
//一个标签
Label label = new Label("+");
//布局
setLayout(new FlowLayout());
add(num1);
add(label);
add(num2);
add(button);
add(num3);
pack();
setVisible(true);
}
}
//监听器类
class MyCalListener implements ActionListener {
//获取三个变量
private TextField num1, num2, num3;
public MyCalListener(TextField num1, TextField num2, TextField num3) {
this.num1 = num1;
this.num2 = num2;
this.num3 = num3;
}
@Override
public void actionPerformed(ActionEvent e) {
//1.获得加数和被加数
int n1= Integer.parseInt(num1.getText());
int n2= Integer.parseInt(num2.getText());
//2.将这个值 + 法运算后，放到第三个框
num3.setText(""+(n1+n2));
//3.清除前两个框
num1.setText("");
num2.setText("");
}
}
6.2实现结果
6.3完全改造为面向对象写法
package com.deng.lesson02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//简易计算器
public class TestCalc02 {
public static void main(String[] args) {
new Calculator02().loadFrame();
}
}
//计算器类
class Calculator02 extends Frame {
//属性
TextField num1, num2, num3;
//方法
public void loadFrame() {
num1 = new TextField(10);//字符数
num2 = new TextField(10);//字符数
num3 = new TextField(20);//字符数
Button button = new Button("=");
button.addActionListener(new MyCalculatorListener(this));
Label label = new Label("+");
//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 {
//获取计算机这个对象,在一个类中组合另一个类
Calculator02 calculator02 = null;
public MyCalculatorListener(Calculator02 calculator02) {
this.calculator02 = calculator02;
}
@Override
public void actionPerformed(ActionEvent e) {
//1.获得加数和被加数
//2.将这个值 + 法运算后，放到第三个框
//3.清除前两个框
int n1=Integer.parseInt(calculator02.num1.getText());
int n2=Integer.parseInt(calculator02.num2.getText());
calculator02.num3.setText(""+(n1+n2));
calculator02.num1.setText("");
calculator02.num2.setText("");
}
}
6.4内部类
-
更好的包装
package com.deng.lesson02; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; //简易计算器 public class TestCalc02 { public static void main(String[] args) { new Calculator02().loadFrame(); } } //计算器类 class Calculator02 extends Frame { //属性 TextField num1, num2, num3; //方法 public void loadFrame() { num1 = new TextField(10);//字符数 num2 = new TextField(10);//字符数 num3 = new TextField(20);//字符数 Button button = new Button("="); Label label = new Label("+"); 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类的属性和方法！ private class MyCalculatorListener implements ActionListener { @Override public void actionPerformed(ActionEvent e) { //1.获得加数和被加数 //2.将这个值 + 法运算后，放到第三个框 //3.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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