uniapp动态添加类名

<template>
    <view>
        <view 
            v-for="(item,index) in menus" 
            class="menu" 
            :class="[activeIndex==index?'menuActive':'']" 
            @click="menuClick" 
            :id="index">
                {{item}}
        </view>
    </view>
</template>
<script>
    var _self;
    export default{
        data(){
            return{
                activeIndex:0,
                menus:[
                    '新闻',
                    '汽车',
                    '读书'
                ]
            }
        },
        onLoad() {
            _self=this;
        },
        methods:{
            menuClick:function(e){
                var aId=e.target.id;
                _self.activeIndex=aId;
            }
        }
    }
</script>