微信小程序实现简易计算器功能

<!--pages/computer.wxml-->
<view class="result">
    <view class="result_num">{{num}}</view>
    <view class="result_op">{{op}}</view>
</view>
<view class="btns">
    <view>
        <view hover-class="bg" bindtap="resetBtn">C</view>
        <view hover-class="bg" bindtap="delBtn">DEL</view>
        <view hover-class="bg" bindtap="opBtn" data-val="%" >%</view>
        <view hover-class="bg"  bindtap="opBtn" data-val="/">÷</view>
    </view>
    <view>
        <view hover-class="bg" data-val="7" bindtap="numBtn">7</view>
        <view hover-class="bg" data-val="8" bindtap="numBtn">8</view>
        <view hover-class="bg" data-val="9" bindtap="numBtn">9</view>
        <view hover-class="bg" bindtap="opBtn" data-val="*">×</view>
    </view>
    <view>
        <view hover-class="bg" data-val="4" bindtap="numBtn">4</view>
        <view hover-class="bg" data-val="5" bindtap="numBtn">5</view>
        <view hover-class="bg" data-val="6" bindtap="numBtn">6</view>
        <view hover-class="bg" bindtap="opBtn" data-val="-">-</view>
    </view>
    <view>
        <view hover-class="bg" data-val="1" bindtap="numBtn">1</view>
        <view hover-class="bg" data-val="2" bindtap="numBtn">2</view>
        <view hover-class="bg" data-val="3" bindtap="numBtn">3</view>
        <view hover-class="bg" bindtap="opBtn" data-val=" "> </view>
    </view>
    <view>
        <view hover-class="bg" data-val="0" bindtap="numBtn">0</view>
        <view hover-class="bg" bindtap="dotBtn">.</view>
        <view hover-class="bg" bindtap="opBtn" data-val="=">=</view>
    </view>
</view>

/* pages/computer.wxss */
page{
    display: flex;
    flex-direction: column;
    height: 100%
}
.result{
    flex: 1;
    background-color: #f3f6fe;
    position: relative;
}
.result_num{
    position: absolute;
    font-size: 27pt;
    bottom: 5vh;
    right: 3vw;
}
.result_op{
    font-size: 15pt;
    position: absolute;
    bottom: 1vh;
    right: 3vw;
}
.btns{
    flex: 1;
    display: flex;
    flex-direction: column;
    font-size: 17pt;
    border-top: 1px solid #ccc;
    border-left: 1px solid #ccc;
}
.btns>view{
    flex: 1;
    display: flex;
}
.btns>view>view{
    flex:1;
    border-right: 1px solid #ccc;
    border-bottom: 1px solid #ccc;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    justify-content: center;
}
.btns>view:last-child>view:first-child{
    flex: 2;
}
.btns>view:first-child>view:first-child{
    color: #f00;
}
.btns>view>view:last-child{
    color: #fc8e00;
}
.bg{
    background-color: #eee;
}

// pages/computer.js
Page({

    /**
     * 页面的初始数据
     */
    data: {
        num:'0',
        op:''
    },
    result:null,
    isClear:false,
    numBtn:function(e){
        var num = e.target.dataset.val
       if(this.data.num==='0'||this.isClear){
        this.setData({num:num})
        this.isClear=false
       }else{
        this.setData({num:this.data.num num})
       }
    },
    opBtn:function(e){
        var op = this.data.op
        var num = Number(this.data.num)
        var val = e.target.dataset.val
        if(val==='/'){
            this.setData({op:'÷'})
        }else if(val==='*'){
            this.setData({op:'×'})
        }else{
            this.setData({op:val})
        }
        //用于多次按计算按钮时，避免重复计算的问题
        if(this.isClear){
            return
        }
        this.isClear=true
        if(this.result===null||this.result===undefined){
            this.result = num
            return
        }
        if(op===' '){
            this.result=this.result num
        }else if(op==='-'){
            this.result=this.result-num
        }else if(op==='×'){
            this.result=(this.result*num).toFixed(2)
        }else if(op==='÷'){
            this.result=this.result/num
        }else if(op==='%'){
            this.result=this.result%num
        }
        this.setData({num:this.result})
    },
    dotBtn:function(){
        if(this.isClear){
            this.setData({num:'0.'})
            this.isClear=false
            return
        }
        if(this.data.num.indexOf('.')>=0){
            return
        }
        this.setData({num:this.data.num '.'})
    },
    delBtn:function(){
        var temp = this.data.num.toString()
        var num = temp.substr(0,this.data.num.length-1);
        this.setData({num:num===''?'0':num})
    },
    resetBtn:function(){
        this.result=null
        this.isClear=false
        this.setData({num:'0',op:''})
    }
})

{
  "navigationBarTitleText":"计算器",
  "navigationBarBackgroundColor":"#fff",
  "navigationBarTextStyle":"black",
  "usingComponents": {}
 
}