当前位置：文江博客知识库 en-US 文档 Web API MediaSession

MediaSession - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The MediaSession interface of the Media Session API allows a web page to provide custom behaviors for standard media playback interactions, and to report metadata that can be sent by the user agent to the device or operating system for presentation in standardized user interface elements.

For example, a smartphone might have a standard panel in its lock screen that provides controls for media playback and information display. A browser on the device can use MediaSession to make browser playback controllable from that standard/global user interface.

Properties

metadata: Returns an instance of MediaMetadata, which contains rich media metadata for display in a platform UI.
playbackState: Indicates whether the current media session is playing. Valid values are none, paused, or playing.

Methods

setActionHandler(): Sets an action handler for a media session action, such as play or pause.
setPositionState(): Sets the current playback position and speed of the media currently being presented.

Examples

The following example creates a new media session and assigns action handlers to it:

if ('mediaSession' in navigator) {
  navigator.mediaSession.metadata = new MediaMetadata({
    title: 'Unforgettable',
    artist: 'Nat King Cole',
    album: 'The Ultimate Collection (Remastered)',
    artwork: [
      { src: 'https://dummyimage.com/96x96',   sizes: '96x96',   type: 'image/png' },
      { src: 'https://dummyimage.com/128x128', sizes: '128x128', type: 'image/png' },
      { src: 'https://dummyimage.com/192x192', sizes: '192x192', type: 'image/png' },
      { src: 'https://dummyimage.com/256x256', sizes: '256x256', type: 'image/png' },
      { src: 'https://dummyimage.com/384x384', sizes: '384x384', type: 'image/png' },
      { src: 'https://dummyimage.com/512x512', sizes: '512x512', type: 'image/png' },
    ]
  });

  navigator.mediaSession.setActionHandler('play', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('pause', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('stop', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('seekbackward', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('seekforward', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('seekto', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('previoustrack', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('nexttrack', function() { /* Code excerpted. */ });
  navigator.mediaSession.setActionHandler('skipad', function() { /* Code excerpted. */ });
}

The following example sets up two functions for playing and pausing, then uses them as callbacks with the relevant action handlers.

const actionHandlers = [
  // play
  [
    'play',
    async function() {
      // play our audio
      await audioEl.play();
      // set playback state
      navigator.mediaSession.playbackState = "playing";
      // update our status element
      updateStatus(allMeta[index], 'Action: play  |  Track is playing...')
    }
  ],
  [
    'pause',
    () => {
      // pause out audio
      audioEl.pause();
      // set playback state
      navigator.mediaSession.playbackState = "paused";
      // update our status element
      updateStatus(allMeta[index], 'Action: pause  |  Track has been paused...');
    }
  ],
]

for (const [action, handler] of actionHandlers) {
  try {
    navigator.mediaSession.setActionHandler(action, handler);
  } catch (error) {
    console.log(`The media session action "${action}" is not supported yet.`);
  }
}