微信小程序实现简单计算器功能

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› JavaScript›JavaScript编程经验

原作者: [db:作者] 来自: [db:来源] 收藏邀请

微信小程序：简单计算器，供大家参考，具体内容如下

对于才接触小程序不久的人来说，想要直接上手一个实用性强的项目难度很大，想要快速熟悉小程序的使用，我们可以先尝试着做一个简单的计算器。

运行截图

计算器对于界面美观的要求并不高，只是一些view以及button控件的组合，所以并不需要在界面上费很多功夫。重要的是逻辑层，之所以选择计算器作为上手的第一个项目，因为计算器的逻辑可简可繁，完全可以适应新手对小程序的掌握程度。

主要代码

js:

Page({
  data: {
   result:"0",
   id1:"clear",
   id2:"back",
   id3:"time",
   id4:"div",
   id5:"mul",
   id6:"sub",
   id7:"add",
   id8:"dot",
   id9:"eql",
   id10:"num_0",
   id11:"num_1",
   id12:"num_2",
   id13:"num_3",
   id14:"num_4",
   id15:"num_5",
   id16:"num_6",
   id17:"num_7",
   id18:"num_8",
   id19:"num_9",
   buttonDot:false,
   is_time:false
  },
  clickButton: function (e) {
   console.log(e);
   var buttonVal = e.target.id;
   var res = this.data.result;
   if(this.data.is_time==true){
    res=0
  }
   var newbuttonDot=this.data.buttonDot;
   var sign;
   if (buttonVal >= "num_0" && buttonVal <= "num_9") {
    var num=buttonVal.split('_')[1];
    if (res == "0" || ((res.length-0) -(length-1)) == "=") {
     res = num;
    }
    else {
     res = res + num;
    }
   }
   else{
    if(buttonVal=="dot")
    {
     if(!newbuttonDot)
     {
      res = res + '.';
     }
    }
    else if(buttonVal=="clear")
    {
     res='0';
    }
    else if(buttonVal=="back")
    {
     var length=res.length;
     if(length>1)
     {
      res=res.substr(0,length-1);
     }
     else{
      res='0'; 
     }
    }
    else if (buttonVal == "div" || buttonVal == "mul" || buttonVal == "sub" || buttonVal == "add")
    {
      if(res.length){}
      else{
        res=JSON.stringify(res)
      }  
      var is_sign=res.substr(res.length-1,res.length)
      if(is_sign=="+"||is_sign=="-"||is_sign=="×"||is_sign=="÷"){
        res=res.substr(0,res.length-1);
      }
     switch(buttonVal){
      case "div":
       sign ='÷';
       break;
      case "mul":
       sign ='×';
       break;
      case "sub":
       sign='-';
       break;
      case "add":
       sign='+';
       break;
     }
     if(!isNaN(res.length))
     {
      res.length-1;
      res=res+sign;
     }
    }
   }
   this.setData({
    is_time:false,
    result: res,
    buttonDot:newbuttonDot,
   });
  },
  equal: function(e){
   var str=this.data.result;
   var item= '';
   var strArray = [];
   var temp=0;
   for(var i=0;i<=str.length;i++){
    var s=str.charAt(i);
    if((s!='' && s>='0' && s<='9') || s=='.'){
     item=item+s;
    }
    else{
     strArray[temp]=item;
     temp++;
     strArray[temp]=s;
     temp++;
     item='';
    }
   }
   if(isNaN(strArray[strArray.length-1]))
   {
    strArray.pop();
   }
   var num;
   var res=strArray[0]*1;
   for(var i=1;i<=strArray.length;i=i+2){
    num=strArray[i+1];
    switch(strArray[i]){
     case "-":
      res = (res-0)- (num-0);
      break;
     case "+":
      res = (res-0) + (num-0);
      break;
     case "×":
      res = (res-0)* (num-0);
      break;
     case "÷":
     if(num!='0')
     {
      res = (res-0)/ (num-0);
     }
     else
     {
      res ='∞';
      break;
     } 
      break;
    }
   }
   this.setData({
    result:res,
   });
  },
  time:function(e){
   var util=require("../../utils/util.js");
   var time=util.formatTime(new Date());
   this.setData({
    result:time,
    is_time:true
   });
  }})

wxml

<!--index.wxml-->
<view class="project_name">简单计算器</view>
<view class="screen_content">
  <view class="screen">{{result}}</view>
</view>
<view class="content"> 
 <view class="buttonGroup">
  <button id="{{id1}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">C</button>
  <button id="{{id2}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">BS</button>
  <button id="{{id3}}" bindtap="time" class="buttonitem color" hover-class="shadow">
  <icon type="waiting" color="#66CC33"></icon>
  </button>
  <button id="{{id4}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">÷</button>
 </view> 
 <view class="buttonGroup"> 
  <button id="{{id17}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">7</button>
  <button id="{{id18}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">8</button>
  <button id="{{id19}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">9</button>
  <button id="{{id5}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">×</button>
 </view>
 <view class="buttonGroup">
  <button id="{{id14}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">4</button>
  <button id="{{id15}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">5</button>
  <button id="{{id16}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">6</button>
  <button id="{{id6}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">-</button>
 </view>
 <view class="buttonGroup">
  <button id="{{id11}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">1</button>
  <button id="{{id12}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">2</button>
  <button id="{{id13}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">3</button>
  <button id="{{id7}}" bindtap="clickButton" class="buttonitem color" hover-class="shadow">+</button>
 </view>
 <view class="buttonGroup">
  <button id="{{id10}}" bindtap="clickButton" class="buttonitem1 color" hover-class="shadow">0</button>
  <button id="{{id8}}" bindtap="clickButton" class="buttonitem1 color" hover-class="shadow">.</button>
  <button id="{{id9}}" bindtap="equal" class="equal" hover-class="shadow">=</button>
 </view>
</view>

wxss:

/**index.wxss**/
page{
  background: #f5f5f5;
 }
 .project_name{
   position:absolute;
   top:25px;
   width:100%;
   text-align: center;
   font-size: 30px;
 }
 .screen_content{
  position: fixed;
  color: #1b1717;
  background: #fff;
  font-size: 40px;
  bottom: 390px;
  text-align: right;
  height:100px;
  width: 100%;
  word-wrap: break-word;
  border-top:1px solid #a8a8a8;
  border-bottom:1px solid #a8a8a8;
 }
 .screen{
  position: absolute;
  font-size: 40px;
  text-align: right;
  bottom:0px;
  width: 96%;
  left:2%;
  word-wrap: break-word;
 }
 .content{
  position: fixed;
  bottom: 0;
 }
 .buttonGroup{
  display: flex;
  flex-direction: row;
 }
 .buttonitem{
  text-align: center;
  line-height: 120rpx;
  width: 25%;
  border-radius: 0;
 }
 .buttonitem1{
  width: 192rpx;
  text-align: center;
  line-height: 120rpx;
  border-radius: 0;
 }
 icon{
  position: absolute;
  top: 20%;
  left: 67rpx;
 }
 .color{
  background: #fff;
 }
 .equal{
   width: 380rpx;
   text-align: center;
   line-height: 120rpx;
   border-radius: 0;
   background: #fff;
 }
 .shadow{
  background: #e9ebe9;
 }