一个简单的四则运算器（Java swing 基础入门）

package pageDesign;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.*;

public class calPage {
    public void getInfo(String infoAll,JLabel jl){
        for (int i =0;i<count;i++) {
            infoAll = infoAll + click.get(i);
        }
        jl.setText(infoAll);
    }//获取数组信息并显示在JLabel中
    public void getValue(JButton jb,JLabel jl){
        jb.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String infoAll = "";
                ArrayList<Double> intNone = new ArrayList<>();//空Double数组，方便置零
                ArrayList<String> none = new ArrayList<>();//空String数组，方便置零
                String input = jb.getText();//获取点击按钮的文本
                if (input == "CE") {
                    click = none;
                    infoAll = "";
                    jl.setText(infoAll);
                }//按到清空键后的函数
                else if(input == "Del") {
                    if(count>0)//当数组内有数据
                    {
                        infoAll="";
                        click.remove(--count);
                        getInfo(infoAll,jl);
                    }
                    else {//当数组内无数据
                        jl.setText("目前输入为空");
                    }
                }//按到删除键后的函数
                else if(input != "Del"&&input!="CE"&&input!="+"&&input!="-"&&input!="*"&&input!="/"&&input!="="){
                    click.add(input);
                    count++;
                     getInfo(infoAll,jl);
                }//正常识别数字按钮数值
                else if(input=="+"||input=="-"||input=="*"||input=="/"){
                click.add(input);
                double s = 0;
                String extra="";
                for(int i = count-1;i>=0;i--)
                {
                    extra = extra + click.get(i);
                }//获取前一段数字
                    s = Double.parseDouble(extra);
                cal.add(s);
                count1 = count;
                count++;
                getInfo(infoAll,jl);
            }//加减乘除四则运算
                else if(input == "="){
                    double s = 0;
                    String extra="";
                    for(int i = count1+1;i<count;i++)
                    {
                        extra = extra + click.get(i);
                    }//获取后一段数字
                    s = Double.parseDouble(extra);
                    cal.add(s);
                    switch (click.get(count1))
                    {
                        case "+":s = cal.get(0)+cal.get(1);break;
                        case "-":s = cal.get(0)-cal.get(1);break;
                        case "*":s = cal.get(0)*cal.get(1);break;
                        case "/":s = cal.get(0)/cal.get(1);break;
                    }//switch判断加减乘除符号
                    infoAll = Double.toString(s);
                    jl.setText(infoAll);
                    cal=intNone;
                    click=none;
                    count = 0;
                    count1 = 0;//全部置零
                }//等于键得数值
            }//添加按钮监听内容
        });
    }//获取按钮数值并进行进一步的计算

    int count = 0;
    int count1 = 0;
    static public ArrayList<Double> cal = new ArrayList<Double>();//需要计算的数值
    private JFrame calAll = new JFrame("计算器 作者：大W的幻想");//主容器
    private JPanel numberScr = new JPanel();//显示数字屏
    private JPanel buttonScr = new JPanel();//显示按钮屏
    private JLabel screen = new JLabel();//显示计算公式
    static public ArrayList<String> click = new ArrayList<String>();//存储点击后的数据
    static public String[] sign = {"7","8","9","+","Del","4","5","6","-","CE","1","2","3","*","(","0",".","=","/",")"};//按钮对应数值
    static private JButton buList = new JButton();//按钮样式
    public calPage(){
        calAll.setBounds(300,200,350,300);
        buttonScr.setLayout(new GridLayout(4,5,5,5));
        for(String info:sign){
            buList = new JButton(info);
            buttonScr.add(buList);
            getValue(buList,screen);
        }//构造所有按钮
        numberScr.add(screen);
        calAll.add(numberScr,BorderLayout.NORTH);
        calAll.add(buttonScr, BorderLayout.SOUTH);
        calAll.setVisible(true);
        calAll.setResizable(false);
        calAll.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }//构造

}

差点忘了，这是主函数的内容

package com.company;
import pageDesign.calPage;
public class Main {
    public static void main(String[] args) {
       new calPage();
    }
}

因为我两个函数分开来写的

代码如上，一些新功能的添加会放在后面的博客中。这个计算器还有（）的功能未加入，不过我会适时的修改以达到正常的使用

本文地址：https://blog.csdn.net/qq_35424155/article/details/111039443