<template>
<view>
<view>
<!-- 选项卡水平方向滑动，scroll-with-animation是滑动到下一个选项时，有一个延时效果 -->
<scroll-view scroll-x="true" scroll-with-animation :scroll-left="scrollLeft">
<view>
<!-- 选项卡类别列表 -->
<view v-for=" (item,index) in category" :key="index"  :class="{'active':isActive==index}" @click="chenked(index)">
{{item.name}}
</view>
</view>
</scroll-view>
</view>
<!-- 选项卡内容轮播滑动显示，current为当前第几个swiper子项 -->
<swiper @change="change" :current="isActive" :style="fullHeight">
<swiper-item>
<scroll-view scroll-y style="height: 100%;">
<view >
选项卡1页面
</view>
</scroll-view> 
</swiper-item>
<swiper-item>
<scroll-view scroll-y style="height: 100%;">
<view >
选项卡2页面
</view>
</scroll-view> 
</swiper-item>
<swiper-item>
<scroll-view scroll-y style="height: 100%;">
<view >
选项卡3页面
</view>
</scroll-view>
</swiper-item>
<swiper-item>
<scroll-view scroll-y style="height: 100%;">
<view >
选项卡4页面
</view>
</scroll-view> 
</swiper-item>
<swiper-item>
<scroll-view scroll-y style="height: 100%;">
<view >
选项卡5页面
    </view>
</scroll-view> 
</swiper-item>
<swiper-item>
<scroll-view scroll-y style="height: 100%;">
<view >
选项卡6页面
    </view>
</scroll-view> 
</swiper-item>
</swiper>
</view>
</template>
<script>
export default {
watch:{
// swiper与上面选项卡联动
currentindex(newval){
this.isActive = newval;
this.scrollLeft = 0;
// 滑动swiper后，每个选项距离其父元素最左侧的距离
for (let i = 0; i < newval - 1; i++) {
this.scrollLeft += this.category[i].width
};
},
},
data() { 
return {
isActive: 0,
index: 0,
currentindex:0,
category:[
{
id:1,
name:'选项卡一',
},
{
id:2,
name:'选项卡二',
},
{
id:3,
name:'选项卡三',
},
{
id:4,
name:'选项卡四',
},
{
id:5,
name:'选项卡五',
},
{
id:6,
name:'选项卡六',
},
],
contentScrollW: 0, // 导航区宽度
scrollLeft: 0, // 横向滚动条位置
fullHeight:"", 
}
},
mounted() {
var that = this;
 //获取手机屏幕的高度，让其等于swiper的高度，从而使屏幕充满
uni.getSystemInfo({
      success: function (res) {
         that.fullHeight ="height:" + res.windowHeight + "px";
  }
});
// 获取标题区域宽度，和每个子元素节点的宽度
this.getScrollW()
},
methods: {
// 获取标题区域宽度，和每个子元素节点的宽度以及元素距离左边栏的距离
getScrollW() {
const query = uni.createSelectorQuery().in(this);
query.select('.tab-scroll').boundingClientRect(data => {
  // 拿到 scroll-view 组件宽度
  this.contentScrollW = data.width
 }).exec();
 query.selectAll('.tab-scroll_item').boundingClientRect(data => {
 let dataLen = data.length;
  for (let i = 0; i < dataLen; i++) {
  //  scroll-view 子元素组件距离左边栏的距离
  this.category[i].left = data[i].left;
 //  scroll-view 子元素组件宽度
 this.category[i].width = data[i].width
}
 }).exec()
},
// 当前点击子元素靠左留一个选项展示，子元素宽度不相同也可实现
chenked(index) {
this.isActive = index;
this.scrollLeft = 0;
for (let i = 0; i < index - 1; i++) {
this.scrollLeft += this.category[i].width
};
},
// swiper滑动时，获取其索引，也就是第几个
change(e){
const {current} = e.detail;
this.currentindex = current;
}, 
}
}
</script>
<style>
page{
height: 100%;
display: flex;
background-color: #FFFFFF;
}
.content{
display: flex;
flex-direction: column;
width: 100%;
flex: 1;
.nav{
border-top: 1rpx solid #f2f2f2;
background-color: #fceeee; 
position: fixed;
z-index: 99;
width: 100%;
align-items: center;
height: 100rpx;
.tab-scroll{
flex: 1;
overflow: hidden;
box-sizing: border-box;
padding-left: 30rpx;
padding-right: 30rpx;
.tab-scroll_box{
display: flex;
align-items: center;
flex-wrap: nowrap;
box-sizing: border-box;
.tab-scroll_item{
line-height: 60rpx;
margin-right: 35rpx;
flex-shrink: 0;
padding-bottom:10px;
display: flex;
justify-content: center;
font-size: 16px;
padding-top: 10px;
}
}
}
}
.swiper-content{
   padding-top: 120rpx;
   flex: 1;
.swiperitem-content{
    background-color: #ffffff;
.nav_item{ 
background-color: #FFFFFF;
padding:20rpx 40rpx 0rpx 40rpx ;
}
}
} 
}
.active {
position: relative;
color: #ff0000;
font-weight: 600;
}
.active::after {
content: "";
position: absolute;
width: 130rpx;
height: 4rpx;
background-color: #ff0000;
left: 0px;
right: 0px;
bottom: 0px;
margin: auto;
}
/* 隐藏滚动条，但依旧具备可以滚动的功能 */
/deep/.uni-scroll-view::-webkit-scrollbar {
display: none
}
</style>