WeChat Mini Program video barrage position random

<!--pages/study/video/videoplay/videoplay.wxml-->
<view class="page-body">
  <view class="page-section tc">
    <video 
      id="myVideo" 
      src="http://wxsnsdy.tc.qq.com/105/20210/snsdyvideodownload?filekey=30280201010421301f0201690402534804102ca905ce620b1241b726bc41dcff44e00204012882540400&bizid=1023&hy=SH&fileparam=302c020101042530230204136ffd93020457e3c4ff02024ef202031e8d7f02030f42400204045a320a0201000400" 
      binderror="videoErrorCallback" 
      danmu-list="{{danmuList}}" 
      enable-danmu 
      danmu-btn 
      show-center-play-btn='{{false}}' 
      show-play-btn="{{true}}" 
      Controls
      picture-in-picture-mode="{{['push', 'pop']}}"
      bindenterpictureinpicture='bindVideoEnterPictureInPicture'
      bindleavepictureinpicture='bindVideoLeavePictureInPicture'
    ></video>
    <view style="margin: 30rpx auto" class="weui-label">Bullet comment content</view>
    <input bindblur="bindInputBlur" class="weui-input" type="text" placeholder="Enter the bullet content here" />
    <button style="margin: 30rpx auto" bindtap="bindSendDanmu" class="page-body-button" type="primary" formType="submit">Send Danmu</button>
    <navigator style="margin: 30rpx auto" url="picture-in-picture" hover-class="other-navigator-hover">
      <button type="primary" class="page-body-button" bindtap="bindPlayVideo">Small window mode</button>
    </navigator>
  </view>
</view>

// pages/study/video/videoplay/videoplay.js
var that;
function getRandomColor() {
  const rgb = []
  for (let i = 0; i < 3; ++i) {
    let color = Math.floor(Math.random() * 256).toString(16)
    color = color.length === 1 ? '0' + color : color
    rgb.push(color)
  }
  return '#' + rgb.join('')
}
 
Page({
  onShareAppMessage() {
    return {
      title: 'video',
      path: 'page/component/pages/video/video'
    }
  },
 
  onReady() {
    that = this;
    this.videoContext = wx.createVideoContext('myVideo')
  },
 
  onHide() {
 
  },
 
  inputValue: '',
  data: {
    src: '',
    danmuList:
    [{
      text: 'The first bullet comment',
      color: '#ff0000',
      time: 1
    }, {
      text: 'The barrage that appeared in the 3rd second',
      color: '#ff00ff',
      time: 3
    }],
  },
 
  bindInputBlur(e) {
    this.inputValue = e.detail.value
  },
 
  bindButtonTap() {
    const that = this
    wx.chooseVideo({
      sourceType: ['album', 'camera'],
      maxDuration: 60,
      camera: ['front', 'back'],
      success(res) {
        that.setData({
          src: res.tempFilePath
        })
      }
    })
  },
 
  bindVideoEnterPictureInPicture() {
    console.log('Enter small window mode')
  },
 
  bindVideoLeavePictureInPicture() {
    console.log('Exit small window mode')
  },
 
  bindPlayVideo() {
    this.videoContext.play()
  },
  bindSendDanmu() {
    // Use loops and random numbers to adjust the position var ranNum = Math.floor(Math.random()*10);
    var danmuList = [];
    for (let index = 0; index < 10; index++) {
      danmuList.push('');
    }
    danmuList[ranNum] = this.inputValue;
    for (let index = 0; index < danmuList.length; index++) {
      this.videoContext.sendDanmu({
        text: danmuList[index],
        color: '#ff0000'
      });
    }
  },
 
  videoErrorCallback(e) {
    console.log('Video error message:')
    console.log(e.detail.errMsg)
  }
})