MediaPositionState dictionary's 位置 property is used when calling the MediaSession 方法 setPositionState() to provide the 用户代理 with the current playback position, in seconds, of the currently-playing media. This information is then, in turn, used by the user agent to provide a user interface which displays media playback information to the viewer.

For example, a browser might use this information along with the 位置 特性和 navigator.mediaSession.playbackState , as well as the session's metadata to provide an integrated common user interface showing the currently playing media as well as standard pause, play, forward, reverse, and other controls.

句法

let positionState = { position: timeInSeconds };
let duration = positionState.duration;
					

A floating-point value indicating the current playback position within the media currently being performed, in seconds. This value should always be zero or more.

范例

In this example, a player for a non-standard media file format, written in JavaScript, uses setInterval() to establish a callback which fires once per second to refresh the position information by calling setPositionState() . If the media is still playing when the interval is fired, setPositionState() is called with an object that specifies the duration, playback rate, and position as reported by a myMedia object that describes the track being played.

If the media is not playing, clearInterval() is used to remove the interval handler.

let positionInterval = window.setInterval(() => {
  if (myMedia.isPlaying) {
    navigator.mediaSession.setPositionState({
      duration: myMedia.trackDurationInSeconds,
      playbackRate: myMedia.playbackRate,
      position: myMedia.trackPlayPositionInSeconds
    });
  } else {
    window.clearInterval(positionInterval);
  }
}, 1000);
					

规范

规范 状态 注释
Media Session Standard
The definition of 'MediaPositionState.position' in that specification.
草案 初始定义。

浏览器兼容性

No compatibility data found. Please contribute data for "api.MediaPositionState.position" (depth: 1) to the MDN 兼容性数据存储库 .

元数据

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