vue-cli中实现全选、单选计算总价格（vue2.0）

<template>
	<div>
		<table>
			<tr>
				<td><input type="checkbox" v-model="checkAll">全选({{checkedCount}})</td>
				<td>产品名称</td>
				<td>价格</td>
				<td>数量</td>
			</tr>
			<tr v-for="(item,$index) in lists">
				<td><span v-show="checkedCount===lists.length || item.checked===true">我被选中</span><input type="checkbox" :value="item.id" v-model="checked" @click="currClick(item,$index)"></td>
				<td>{{item.productName}}</td>
				<td>{{item.price}}</td>
				<td>{{item.count}}</td>
			</tr>
			<tr>
				总价：{{totalMoney}}
			</tr>
		</table>
	</div>
</template>
<script>
	export default{
		data() {
			return {
				checked:[],
				totalPrice:[],
				lists : [
					{
						productName:'产品1',
						price:'24',
						count:'3',
						id:1
					},
					{
						productName:'产品2',
						price:'25',
						count:'6',
						id:2
					},
					{
						productName:'产品3',
						price:'54',
						count:'7',
						id:3
					}
				]
			}
		},
		computed:{
			totalMoney:function(item,index){
				let sum = 0;
				for(let i=0;i<this.totalPrice.length;i++){
					sum += this.totalPrice[i];
				};
				return sum;
			},
			checkAll: {
			    get: function() {
			        return this.checkedCount == this.lists.length;
			    },
			    set: function(value){
			      	var _this = this;
			        if (value) {
			        	this.totalPrice = [];
		        		this.checked = this.lists.map(function(item) {
		        			item.checked = true;
				            let total = item.price*item.count;
							_this.totalPrice.push(total);
							return item.id
						})
			        }else{
			            this.checked = [];
			            this.totalPrice=[];
			            this.lists.forEach(function(item,index){
							item.checked = false;
			            });
			        }
			    }
		    },
		    checkedCount: {
		        get: function() {
		        	return this.checked.length;
		        }
		    }
		},
		methods:{
			currClick:function(item,index){
				var _this = this;
				if(typeof item.checked == 'undefined'){
					this.$set(item,'checked',true);
						let total = item.price*item.count;
						this.totalPrice.push(total);
						console.log(this.totalPrice);
				}else{
					item.checked = !item.checked;
					if(item.checked){
						this.totalPrice = [];
						this.lists.forEach(function(item,index){
							if(item.checked){
								let total = item.price*item.count;
								_this.totalPrice.push(total);
							}
						});
					}else{
						this.totalPrice = [];
						this.lists.forEach(function(item,index){
							if(item.checked){
								let total = item.price*item.count;
								_this.totalPrice.push(total);
							}
						});
					}
				}
			}
		}
	}
</script>
<style>
	tr td{
		width:200px;
		background: #eee;
		padding:10px 0;
	}

</style>

效果：