在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

这是 实验性技术
检查 浏览器兼容性表格 要小心谨慎在生产中使用这之前。

direction 特性为 Web 动画 API dictionary EffectTiming indicates an animation's playback direction along its timeline, as well as its behavior when it reaches the end of an iteration

Element.animate() , KeyframeEffectReadOnly() ，和 KeyframeEffect() all accept an object of timing properties including direction. 值 direction corresponds directly to AnimationEffectTimingReadOnly.direction in timing objects returned by AnimationEffectReadOnly , KeyframeEffectReadOnly ，和 KeyframeEffect .

句法

var timingProperties = {
  direction: "normal" | "reverse" | "alternate" | "alternate-reverse"
};
timingProperties.direction = "normal" | "reverse" | "alternate" | "alternate-reverse";
					

值

A DOMString which specifies the direction in which the animation should play as well as what to do when the playback reaches the end of the animation sequence in the current direction. It can take one of the following values, with the default being "normal" :

"normal"

The animation runs forwards, from beginning to end, in the way we experience the flow of time.

"reverse "

The animation runs backwards, or "rewinds."

"alternate"

The animation switches direction after each iteration, going forward through the animation sequence the first iteration, then backward through the sequence the second iteration, and so forth.

"alternate-reverse"

Similar to "alternate", except the animation playback starts by going from the end of the animation sequence toward the beginning the first iteration, then goes forward during the second, and so forth.

范例

在 Forgotten Key example, Alice waves her arm up and down by passing her an alternate value for her direction 特性：

// Get Alice's arm, and wave it up and down
document.getElementById("alice_arm").animate([
  { transform: 'rotate(10deg)' },
  { transform: 'rotate(-40deg)' }
], {
  easing: 'steps(2, end)',
  iterations: Infinity,
  direction: 'alternate',
  duration: 600
});
					

规范

规范	状态	注释
Web 动画 The definition of 'direction' in that specification.	工作草案	编者草案。

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
direction	Chrome 52	Edge ≤79	Firefox 63	IE No	Opera Yes	Safari No	WebView Android 52	Chrome Android 52	Firefox Android 63	Opera Android No	Safari iOS No	Samsung Internet Android Yes

图例

完整支持

完整支持

不支持

不支持

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

另请参阅

• Web 动画 API
• Element.animate() , KeyframeEffectReadOnly() ，和 KeyframeEffect() all accept an object of timing properties including this one.
• The value of this property corresponds to the one in AnimationEffectTimingReadOnly (which is the timing object for AnimationEffectReadOnly , KeyframeEffectReadOnly ，和 KeyframeEffect ).
• CSS's animation-direction

元数据

• 最后修改： Aug 11, 2020

相关话题

1. Web 动画 API
2. EffectTiming
3. 特性

   1. delay
   2. direction
   3. duration
   4. easing
   5. endDelay
   6. fill
   7. iterations
   8. iterationStart
4. Web 动画相关页面

   1. 动画
   2. AnimationEffect
   3. AnimationEvent
   4. AnimationPlaybackEvent
   5. AnimationTimeline
   6. Document.getAnimations()
   7. Document.timeline
   8. DocumentTimeline
   9. Element.animate()
   10. KeyframeEffect