AWT-简易计算器，组合+内部类回顾复习

AWT-简易计算器，组合+内部类回顾复习

opp原则：组合，大于继承！

class A extend B{
}
class A{
    public B b;
}

---

目前代码

package com.deng.lesson2;

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

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3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.清除前两个框
        num1.setText("");
        num2.setText("");
    }
}

---

完全改造为面向对象写法

package com.deng.lesson2;

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(){
        //3个文本框
        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 MyCalculatorListener2(this));

        //布局
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(button);
        add(num3);
        pack();
        setVisible(true);
    }
}
//监听器类
class MyCalculatorListener2 implements ActionListener {
    //获取计算器这个对象，在一个类中组合另一个类
    Calculator02 calculator02 =null;

       public MyCalculatorListener2(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("");
           }
        }

---

内部类

package com.deng.lesson2;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//简易计算器
public class TestCalc03 {
    public static void main(String[] args) {
        new Calculator03().loadFrame();
    }
}
//计算器类
class Calculator03 extends Frame{
    //属性、
    TextField num1,num2,num3;
    //方法
    public void loadFrame(){
        //3个文本框
        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 MyCalculatorListener3());

        //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 MyCalculatorListener3 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("");
        }
    }
}