keyframeslink

使用说明link

和 animate() 调用一起使用。关键帧动画不会直接在当前状态和目标状态之间应用动画，而是描述在动画弧线的哪个时间点上应用哪个样式。 详情参见 CSS 关键帧动画。

Use with the animate() call. Instead of applying animations from the current state to the destination state, keyframes describe how each style entry is applied and at what point within the animation arc. Compare CSS Keyframe Animations.

用法link

Usagelink

下面的例子中，偏移值描述了每个 backgroundColor 值应该何时应用上去。开始时的颜色是红色，在总时间的 20% 处变为蓝色。

In the following example, the offset values describe when each backgroundColor value is applied. The color is red at the start, and changes to blue when 20% of the total time has elapsed.

      
        content_copy
      
      // the provided offset values
animate("5s", keyframes([
  style({ backgroundColor: "red", offset: 0 }),
  style({ backgroundColor: "blue", offset: 0.2 }),
  style({ backgroundColor: "orange", offset: 0.3 }),
  style({ backgroundColor: "black", offset: 1 })
]))
    

如果没有指定 offset 值，则会自动计算偏移量。

If there are no offset values specified in the style entries, the offsets are calculated automatically.

      
        content_copy
      
      animate("5s", keyframes([
  style({ backgroundColor: "red" }) // offset = 0
  style({ backgroundColor: "blue" }) // offset = 0.33
  style({ backgroundColor: "orange" }) // offset = 0.66
  style({ backgroundColor: "black" }) // offset = 1
]))