最近自己在网上看到别人使用 vue 进行自定义 video 的操作。加上不久前实现了 angular 自定义 video 的相关需求， 遂来记录一下，作为交流思考。

实现的功能如下：

• 播放 / 停止
• 快退 / 快进 / 倍速
• 声音开 / 声音关
• 进入全屏 / 退出全屏
• 进入画中画 / 退出画中画 【安卓平板不支持，不建议使用】
• 经过时长 / 总时长
• 播放进度条功能：支持点击，拖拽进度
• 声音进度条功能：支持点击，拖拽进度

如图：

下面我们来一一实现：

这里的重点不在布局，我们简单来定义一下：

<!-- app.component.html -->

<div class="video-page">
  <div class="video-tools">
    <button nz-button nzType="primary" (click)="play('btn')" style="margin-right: 12px;">播放 </button>
    <button nz-button nzType="primary" (click)="pause('btn')">暂停 </button>
    <ng-container>
      <button nz-button nz-dropdown [nzDropdownMenu]="menuForward" nzPlacement="bottomCenter" style="margin: 0 12px;">快进 </button>
        <nz-dropdown-menu #menuForward="nzDropdownMenu">
          <ul nz-menu>
            <li nz-menu-item (click)="forwardSecond(10)">快进 10 s</li>
            <li nz-menu-item (click)="forwardSecond(20)">快进 20 s</li>
          </ul>
        </nz-dropdown-menu>
    </ng-container>
    <ng-container>
      <button nz-button nz-dropdown [nzDropdownMenu]="menuBack" nzPlacement="bottomCenter">快退 </button>
        <nz-dropdown-menu #menuBack="nzDropdownMenu">
          <ul nz-menu>
            <li nz-menu-item (click)="retreatSecond(10)">快退 10 s</li>
            <li nz-menu-item (click)="retreatSecond(20)">快退 20 s</li>
          </ul>
        </nz-dropdown-menu>
    </ng-container>
    <ng-container>
      <button nz-button nz-dropdown [nzDropdownMenu]="speedUp" nzPlacement="bottomCenter" style="margin: 0 12px;">倍速 </button>
        <nz-dropdown-menu #speedUp="nzDropdownMenu">
          <ul nz-menu>
            <li nz-menu-item (click)="speedUpVideo(1)">正常</li>
            <li nz-menu-item (click)="speedUpVideo(2)">2 倍</li>
            <li nz-menu-item (click)="speedUpVideo(4)">4 倍</li>
          </ul>
        </nz-dropdown-menu>
    </ng-container>
    <button nz-button nzType="primary" (click)="openOrCloseVoice()">声音开 / 声音关 </button>
    <button nz-button nzType="primary" style="margin: 0 12px;" (click)="toFullScreen()">全屏 </button>
    <br />
    <button nz-button nzType="primary" style="margin-top: 12px;" (click)="entryInPicture()">进入画中画 ️ 安卓平板不支持</button>
    <button nz-button nzType="primary" style="margin: 12px 12px 0 12px;" (click)="exitInPicture()">退出画中画 ️ 安卓平板不支持</button>
    <br />
    <div style="display: flex; justify-content: flex-start; align-items: center; margin: 12px 0;">
      经过时长 / 总时长 ：  {{ currentTime }}  / {{ totalTime }}
    </div>
    <!-- 进度条 -->
    <div style="display: flex; justify-content: flex-start; align-items: center; margin: 12px 0;">
      进度条：
      <div
        class="custom-video_control-bg"
        (mousedown)="handleProgressDown($event)"
        (mousemove)="handleProgressMove($event)"
        (mouseup)="handleProgressUp($event)"
      >
        <div
          class="custom-video_control-bg-outside"
          id="custom-video_control-bg-outside"
        >
          <span
            class="custom-video_control-bg-inside"
            id="custom-video_control-bg-inside"
          ></span>
          <span
            class="custom-video_control-bg-inside-point"
            id="custom-video_control-bg-inside-point"
          ></span>
        </div>
      </div>
    </div>
    <div style="display: flex; justify-content: flex-start; align-items: center; margin: 12px 0;">
      声音条：
      <div class="custom-video_control-voice">
        <span class="custom-video_control-voice-play">
          <i nz-icon nzType="sound" nzTheme="outline"></i>
        </span>
        <div
          class="custom-video_control-voice-bg"
          id="custom-video_control-voice-bg"
          (mousedown)="handleVolProgressDown($event)"
          (mousemove)="handleVolProgressMove($event)"
          (mouseup)="handleVolProgressUp($event)"
        >
          <div 
            class="custom-video_control-voice-bg-outside"
            id="custom-video_control-voice-bg-outside"
          >
            <span 
              class="custom-video_control-voice-bg-inside"
              id="custom-video_control-voice-bg-inside"
            ></span>
            <span 
              class="custom-video_control-voice-bg-point"
              id="custom-video_control-voice-bg-point"
            ></span>
          </div>
        </div>
      </div>
    </div>
  </div>
  <div class="video-content">
    <video id="video" class="video" style="width: 100%" poster="assets/poster.png">
      <source type="video/mp4" src="assets/demo.mp4">
      Sorry, your browser doesn't support.
    </video>
  </div>
</div>

这里使用了 angular ant design，之前写了一篇相关文章，还不熟悉的读者可前往 Angular 结合 NG-ZORRO 快速开发

播放 / 停止

这里直接调用 video 对象的方法 play() 和 pause():

// app.component.ts

// 播放按钮事件
play(flag: string | undefined) {
  if(flag) this.videoState.playState = true
  this.videoState.play = true
  this.video.play()
}
// 暂停按钮事件
pause(flag: string | undefined): void {
  if(flag) this.videoState.playState = false
  this.video.pause()
  this.videoState.play = false
}

这里自定义的 play 和 pause 方法加上了一个标志，对下下面要讲的进度条的控制有帮助，上面的代码可以更加简洁，读者可以简写下。

快退 / 快进 / 倍速

这里的快退，快进和倍速设置了不同的选项，通过参数进行传递：

// app.component.ts

// 快进指定的时间
forwardSecond(second: number): void {
  this.video.currentTime += second; // 定位到当前的播放时间 currentTime
}

// 后退指定的时间
retreatSecond(second: number): void {
  this.video.currentTime -= second
}

// 倍速
speedUpVideo(multiple: number): void {
  this.video.playbackRate = multiple; // 设定当前的倍速 playbackRate
}

声音开 / 声音关

声音的开关使用 video 的 muted 属性即可：

// app.component.ts

// 开或关声音
openOrCloseVoice(): void {
  this.video.muted = !this.video.muted;
}

进入全屏 / 退出全屏

全屏的操作也是很简单，使用 webkitRequestFullScreen

// app.component.ts

// 全屏操作
toFullScreen(): void {
  this.video.webkitRequestFullScreen()
}

全屏后，按 esc 可退出全屏

进入画中画 / 退出画中画

画中画相当于弹窗缩小视频~

// app.component.ts

// 进入画中画
entryInPicture(): void {
  this.video.requestPictureInPicture()
  this.video.style.display = "none"
}

// 退出画中画
exitInPicture(): void {
  if(this.document.pictureInPictureElement) {
    this.document.exitPictureInPicture()
    this.video.style.display = "block"
  }
}

设置 video 的样式，是为了看起来不突兀...

经过时长 / 总时长

记录视频的总时长和视频当前的播放时长。我们已经来组件的时候就获取视频的元信息，得到总时长；在视频播放的过程中，更新当前时长。

// app.component.ts

// 初始化 video 的相关的事件
initVideoData(): void {
  // 获取视频的总时长
  this.video.addEventListener('loadedmetadata', () => {
    this.totalTime = this.formatTime(this.video.duration)
  })
  // 监听时间发生更改
  this.video.addEventListener('timeupdate', () => {
    this.currentTime = this.formatTime(this.video.currentTime) // 当前播放的时间
  })
}

formatTime 是格式化函数

播放进度条功能

监听鼠标的点击，移动，松开的事件，对视频的播放时间和总事件进行相除，计算百分比。

// app.component.ts

// 进度条鼠标按下
handleProgressDown(event: any): void {
  this.videoState.downState = true
  this.pause(undefined);
  this.videoState.distance = event.clientX + document.documentElement.scrollLeft - this.videoState.leftInit;
}
// 进度条 滚动条移动
handleProgressMove(event: any): void {
  if(!this.videoState.downState) return
  let distanceX = (event.clientX + document.documentElement.scrollLeft) - this.videoState.leftInit
  if(distanceX > this.processWidth) { // 容错处理
    distanceX = this.processWidth;
  }
  if(distanceX < 0) { // 容错处理
    distanceX = 0
  }
  this.videoState.distance = distanceX
  this.video.currentTime = this.videoState.distance / this.processWidth * this.video.duration
}
// 进度条 鼠标抬起
handleProgressUp(event: any): void {
  this.videoState.downState = false
  // 视频播放
  this.video.currentTime = this.videoState.distance / this.processWidth * this.video.duration
  this.currentTime = this.formatTime(this.video.currentTime)
  if(this.videoState.playState) {
    this.play(undefined)
  }
}

这里需要计算进度条的位置，来获取点击进度条的百分比，之后更新视频的当前播放时间。当然，我们还得有容错处理，比如进度条为负数时候，当前播放时间为0。

声音进度条

我们实现了播放进度条的操作，对声音进度条的实现就很容易上手了。声音进度条也是监听鼠标的点击，移动，松开。不过，这次我们处理的是已知声音 div 的高度。

// app.component.ts

// 声音条 鼠标按下
handleVolProgressDown(event: any) {
  this.voiceState.topInit = this.getOffset(this.voiceProOut, undefined).top
  this.volProcessHeight = this.voiceProOut.clientHeight
  this.voiceState.downState = true //按下鼠标标志
  this.voiceState.distance = this.volProcessHeight - (event.clientY + document.documentElement.scrollTop - this.voiceState.topInit) 
}
// 声音 滚动条移动
handleVolProgressMove(event: any) {
  if(!this.voiceState.downState) return
    let disY = this.voiceState.topInit + this.volProcessHeight - (event.clientY + document.documentElement.scrollTop)
    if(disY > this.volProcessHeight - 2) { // 容错处理
      disY = this.volProcessHeight - 2
    }
    if(disY < 0) { // 容错处理
      disY = 0
    }
    this.voiceState.distance = disY
    this.video.volume = this.voiceState.distance / this.volProcessHeight
    this.videoOption.volume = Math.round(this.video.volume * 100)
}
// 声音 鼠标抬起
handleVolProgressUp(event: any) {
  this.voiceState.downState = false //按下鼠标标志
  let voiceRate =  this.voiceState.distance / this.volProcessHeight
  if(voiceRate > 1) {
    voiceRate = 1
  }
  if(voiceRate < 0) {
    voiceRate = 0
  }
  this.video.volume = voiceRate
  this.videoOption.volume = Math.round(this.video.volume * 100); // 赋值给视频声音
}

如图：

效果演示

完成了上面的内容，我们以一个 gif 图来展示效果：

全屏，声音和画中画比较难截图，Gif 上体现不来