Uniapp custom vue navigation menu component completes menu dynamic highlighting

    <script>
	export default {
		name: "tab",
		data() {
			return {
				 activeIndex:0
			};
		},
		// 组件实例的作用域是孤立的。这意味着不能（也不应该）在子组件的模板中直接饮用父组件的数据。要让子组件使用父组件的数据，需要通过子组件的 props 选项。子组件要显示的用 props 声明它期望获得的数据
		// 借助watch可以监听data或者 props 值的变化
		watch:{
			tabIndex(newVal,oldVal)
			{
				// console.log(newVal,oldVal);
				this.activeIndex = newVal
			}
		},
		//接收来自主组件的值 list  
		props: {
			list: {
				type: Array,
				default () {
					return []
				}
			} 

		},
		methods:{
			clickTab(item,index)
			{
				// console.log(item,index);
				this.activeIndex = index
				// tab是自定义事件名 派发给组件的调用者 index.vue
				this.$emit("tab",{
					data:item,
					index:index
				})
			}
		}
	}
</script>

    <style>
    .tab{
        display: flex;
        width: 100%;
        border-bottom: 1px solid #f5f5f5;
        .tab-srcoll{
        display: flex;
        overflow: hidden;
        box-sizing: border-box;
            .tab-srcoll-box{
                display: flex;
                height: 45px;
                align-items: center;
                flex-wrap: nowrap;
                box-sizing: border-box;
                .tab-srcoll-item{
                    color: #333;
                    flex-shrink: 0;
                    font-size: 14px;
                    padding: 0 10px;
                    &.active{
                        color: $chloe-base-color;
                    }
                }
            
            }
        }
    }
</style>

    <template>
	<view class="home">
		<tab :list="list" @tab="tab" ></tab>
	</view>
    </template>

    <script>
	export default {
		data() {
			return {
				list: [],
				activeIndex:0
			};
		},
		onLoad() {
			this.getTabList()
			 
		},
		onShow(){
			
		},
		methods: {
			tab({
				data,
				index
			}) {
				// console.log(data.catname,index);
				this.activeIndex = index
			},
			
			async getTabList() {
				const res = await this.$myRequest({
					url: &#39;tab&#39;
				})
				const {
					data
				} = res
				this.list = data
			} 

		}
	}
</script>

    const BASE_URL = 'http://inews.io/'这里可以换成你后端接口的域名
export const myRequest = (options) => {
	const {
		url,
		method,
		data,
		timeout
	} = options
	return new Promise((resolve, reject) => {
		uni.request({
			url: BASE_URL + url,
			method: method || 'GET',
			data: data || {},
			timeout:timeout || 3000,
			success: (res) => {
				if (res.statusCode !== 200) {
					uni.showToast({
						title: '请求数据失败',
						duration: 1000,
						icon: 'none'
					});
				}

				resolve(res)
			},
			fail: (err) => {
				uni.showToast({
					title: '请求接口失败',
					duration: 1000,
					icon: 'none'
				});
				reject(err)
			}

		})
	})
}