我们的志愿者还没有将这篇文章翻译为 中文 (简体)。加入我们帮助完成翻译！
The HTMLMediaElement.readyState property indicates the readiness state of the media.
Syntax
var readyState = audioOrVideo.readyState;
Value
An unsigned short. Possible values are:
| Constant | Value | Description |
|---|---|---|
| HAVE_NOTHING | 0 | No information is available about the media resource. |
| HAVE_METADATA | 1 | Enough of the media resource has been retrieved that the metadata attributes are initialized. Seeking will no longer raise an exception. |
| HAVE_CURRENT_DATA | 2 | Data is available for the current playback position, but not enough to actually play more than one frame. |
| HAVE_FUTURE_DATA | 3 | Data for the current playback position as well as for at least a little bit of time into the future is available (in other words, at least two frames of video, for example). |
| HAVE_ENOUGH_DATA | 4 | Enough data is available—and the download rate is high enough—that the media can be played through to the end without interruption. |
Examples
This example will listen for audio data to be loaded for the element `example`. It will then check if at least the current playback position has been loaded. If it has, the audio will play.
<audio id="example" preload="auto"> <source src="sound.ogg" type="audio/ogg" /> </audio>
var obj = document.getElementById('example');
obj.addEventListener('loadeddata', function() {
if(obj.readyState >= 2) {
obj.play();
}
});
Specifications
| Specification | Status | Comment |
|---|---|---|
| WHATWG HTML Living Standard The definition of 'HTMLMediaElement.readyState' in that specification. |
Living Standard | No change from HTML5 |
| HTML5 The definition of 'HTMLMediaElement.readyState' in that specification. |
Recommendation | Initial definition. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | (Yes) | 3.5 (1.9.1) [1] | 9 | ? | ? |
| Feature | Android | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | ? | (Yes) | (Yes) |
[1] The NETWORK_LOADED state was removed to align with the HTML spec in Gecko 2.0 (Firefox 4 / Thunderbird 3.3 / SeaMonkey 2.1).
See also
- The interface defining it,
HTMLMediaElement.