| evt | 要添加的 AnimationEvent。 |
将一个动画事件添加到该剪辑中。
Note that events added with AddEvent persist until play mode
is exited or the is player quit. If you want to add an event to a clip persistently,
use AnimationUtility.SetAnimationEvents from the Unity editor.
另请参阅：AnimationEvent、AnimationUtility 类。