利用计算属性实现购物车功能，计算属性总是会依赖于自身使用的数组，在和购物车进行交互（全选、加减数量、删除）时总是应该对数组的元素进行操作，在对数组操作后，计算属性则会进行重新渲染视图，因而你只需要关心你的数据即可。
代码如下：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>购物车</title>
<style>
[v-cloak]{
display: none;
}
table{
border: 1px solid #e9e9e9;
border-collapse: collapse;
border-spacing: 0;
empty-cells: show;
}
th,td{
padding: 8px 16px;
border: 1px solid #e9e9e9;
text-align: left;
}
th{
background: #f7f7f7;
color: #5c6b77;
font-weight: 600;
white-space: normal;
}
</style>
</head>
<body>
<div id="app" v-cloak>
<template v-if="goods.length">
<table>
<tr>
<th>序号</th>
<th>商品名称</th>
<th>商品单价</th>
<th>购买数量</th>
<th>操作</th>
</tr>
<tr v-for='(goods,index) in goods'>
<td>
<input type="checkbox" :checked="goods.is_true" @click="handlerCancel(index,$event)" >
{{ index + 1 }}
</td>
<td>{{ goods.name }}</td>
<td>{{ goods.price }}</td>
<td>
<button @click='handlerReduce(index)'
:disabled="goods.count === 1"
>-</button>
{{ goods.number }}
<button @click='handlerAdd(index)'>+</button>
</td>
<td>
<button type="button" @click="handlerRemove(index)">移除</button>
</td>
</tr>
</table>
全选<input type="checkbox" :checked="is_all" @click="handleAllSelect" >
<span>商品总价:{{ total_val }}</span>
</template>
</div>
<script src="https://unpkg.com/vue/dist/vue.min.js"></script>
<script>
var app = new Vue({
el:'#app',
data:{
goods:[
{id:1,name:'apple',price:10.00,number:1,is_true:1}, //is_true 是否选中
{id:2,name:'banana',price:8.00,number:10,is_true:1},
{id:3,name:'orange',price:19.00,number:5,is_true:1}
]
},
computed: {
total_val:function(){
var prices = 0;
for(var i = 0;i<this.goods.length;i++){
var item = this.goods[i];
if(item.is_true){ //如果选中则增加到总价中
prices += item.price*item.number
}
}
return prices.toString().replace(/B(?=(d{3})+$)/g,',');
},
is_all:function(){
return this.goods.every(function(val){return val.is_true}); //遍历返回数组中的是否选中的值
}
},
mounted () {
},
methods: {
handlerAdd:function(index){
this.goods[index].number++;
},
handlerReduce:function(index){
if(this.goods[index].number === 1) return;
this.goods[index].number--;
},
handlerRemove:function(index){
this.goods.splice(index,1);
},
handlerCancel:function(index,event){
this.goods[index].is_true = event.target.checked;
},
handleAllSelect:function(){
this.goods.map(function(item,index){ //map函数更改是否全选
item.is_true = event.target.checked;
})
}
}
})
</script>
</body>
</html>