简易计算器，组合+内部类回顾复习 代码优化

简易计算器，组合+内部类回顾复习！

oop原则；组合，大于继承！

class A extend B{
    
}

class A{
    public 	B b;
}

1.功能实现、面向过程

package com.zhang.lesson02;

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

//简易计算器
public class TestCalc {
    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        windowsclose(calculator);
    }

    private static void windowsclose(Calculator frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
//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
        //一个按钮
        Button button = new Button("=");
        //添加监听
        button.addActionListener(new MyCalculatorListener(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 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());//将string类型转换为 int类型
        int n2 = Integer.parseInt(num2.getText());//将string类型转换为 int类型

        //2.将这个值加法运算后，放到第三个框
        num3.setText(""+(n1+n2));
        //3.清除前两个框
        num1.setText(" ");
        num2.setText(" ");
    }
}

2.代码优化

2.1组合、完全改造为面向对象

package com.zhang.lesson02;

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

//简易计算器
public class TestCalc {
    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        calculator.loadFrame();
        windowsclose(calculator);
    }
    //关闭窗口事件
    private static void windowsclose(Calculator frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
//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);//字符数
        num2 = new TextField(10);//字符数
        num3 = new TextField(20);//字符数
        //一个按钮
        Button button = new Button("=");
        //一个标签
        Label label = new Label("+");
        //添加监听
        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.将这个值加法运算后，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("");
    }

}

2.2内部类

• 更好的包装
• 畅通无阻的访问外部的属性和方法

package com.zhang.lesson02;

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

//简易计算器
public class TestCalc {
    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        calculator.loadFrame();
        windowsclose(calculator);
    }
    //关闭窗口事件
    private static void windowsclose(Calculator frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
//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);//字符数
        num2 = new TextField(10);//字符数
        num3 = new TextField(20);//字符数
        //一个按钮
        Button button = new Button("=");
        //一个标签
        Label label = new Label("+");
        //添加监听
        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
    private class MyCalculatorListener implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            //1.获得加数和被加数
            //2.将这个值加法运算后，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("");
        }

    }

}
        //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("");
        }

    }

}