video标签层级很高，尝试了添加z-index，但无效果
通过查阅资料，得知cover-view层级比video层级高

效果图

需求是为了使直播时，可选是原画/流畅

解决方案

首先，在pages.json中配置右上角的图标

{"path" : "pages/event/live","style" : {"navigationBarTitleText": "直播详情","navigationBarTextStyle":"white","disableScroll": true,"app-plus":{"titleNView":{"backgroundColor":"#010001","buttons":[{"fontSrc": "/static/iconfontapp.ttf","text": "\ue66f","fontSize": "22px","color": "#FFFFFF"},{"fontSrc": "/static/iconfontapp.ttf","text": "\ue60b","fontSize": "22px","color": "#FFFFFF"}]}}}},

然后在需要展示这个按钮的页面，加上操作方法

<template><view v-if="liveUrl"><video class="v-video-play"  autoplay:src="liveUrl" controls:show-progress="false"><template v-if="speedShow && range && range.length"><cover-view class="cover-box w100"></cover-view><cover-view v-for="(item, index) in range" :key="index" @click="selectitem(item.value)" class="sb-txt cf" :class="[{'cred': item.value == rangeValue},`f${index + 1}`]">{{ item.text }}</cover-view></template></video></view>
</template>
<script>
export default {data() {return {rangeValue: 'FD', // 默认流畅range: [], // 画质选项的列表speedShow: false // 是否点击了切换的按钮}},onNavigationBarButtonTap(button) {let _event = this.eventif(button.index === 0) {//如果点击的是分享按钮shareWx({title: _event.title,summary: '活动直播 - 墨天轮',href: domain + `/event/live/${_event.id}`,imageUrl: _event.shareImageUrl})} else if (button.index === 1) {//如果点击的是清晰度切换按钮this.speedShow = !this.speedShow}},
}
</script>