使用video作为一个内容盒子，在video里使用swiper嵌套两个video实现全屏状态下平滑切换视频，点击全屏的时候video盒子全屏，swiper内video在ios系统下不能全屏。

之所以使用video里嵌套video是为了 在全屏状态下更流畅的切换视频，修改src的话会有加载过程，屏幕会黑一下

复现代码

<video class="video-player-box" id="video_player_box" controls="{{false}}">

  <video autoplay="{{true}}" class="demo" object-fit="cover" controls="{{false}}" src="https://lf9-cdn-tos.bytecdntp.com/cdn/expire-1-M/byted-player-videos/1.0.0/xgplayer-demo-720p.mp4"></video>

  <view class="controll-box">

    <view class="button" bind:tap="fullscreen">全屏</view>

    <view class="button" bind:tap="cancelfullscreen">取消全屏</view>

  </view>

</video>

// index.js
Page({
  onLoad(){
   this.data.playerBox=wx.createVideoContext('video_player_box', this)
  },
  fullscreen:function(){
    this.data.playerBox.requestFullScreen({direction:90})
  },
  cancelfullscreen:function(){
    this.data.playerBox.exitFullScreen();
  }
})

.video-player-box{
  width: 100%;
  position: relative;
}
.controll-box{
  position: absolute;
  bottom: 0px;
  width: 100%;
  height: 50px;
  display: flex;
  justify-content: center;
  align-items: center;
  color: red;
}
.demo{
  width: 100%;
  height: 100%;
}
.button{
  margin: 10px;
}