vue点击实现箭头的向上与向下

 <span class="iconfont icon-jiantouarrow486" v-if="show" @click="ptOpenDowOrUp()"></span>
 <span class="iconfont icon-jiantouarrow492" v-else></span>

 var vm = new Vue({
        el:‘#app‘,
        data:{
            
            show:true,
            
        },
        methods:{
            ptOpenDowOrUp:function () {
              vm.show = !vm.show

            },
           
        }
    })