简易计算器、回顾组合内部类

oop原则：组合，大于继承!

class A extends B{

}

class A{
    public B{
    
    }
}

package com.wang.gui;

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 MyCalculatorListener(num1,num2,num3));

        //1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 MyCalculatorListener implements ActionListener {
    //获取三个变量
    private TextField num1, num2, num3;

    public MyCalculatorListener(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.清楚前两个框
        num1.setText("");
        num2.setText("");
    }
}

package com.wang.gui;

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().loadFrame();
    }
}

//计算器类
class Calculator extends Frame {
    //属性
    TextField num1;
    TextField num2;
    TextField 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(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) {
        //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.清楚前两个框

        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("");
    }
}

package com.wang.gui;

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().loadFrame();
    }
}

//计算器类
class Calculator extends Frame {
    //属性
    TextField num1;
    TextField num2;
    TextField 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.清楚前两个框

            int n1 = Integer.parseInt(num1.getText());
            int n2 = Integer.parseInt(num2.getText());
            num3.setText(""+(n1+n2));
            num1.setText("");
            num2.setText("");
        }
    }
}