interface in UnityEngine.Experimental.UIElements
切换到手册使类能够处理事件的接口。
| HandleEvent | 处理事件。 |
| HasBubbleUpHandlers | Return true if event handlers for the event propagation BubbleUp phase have been attached on this object. |
| HasTrickleDownHandlers | Returns true if event handlers, for the event propagation TrickleDown phase, are attached to this object. |
| SendEvent | Sends an event to the event handler. |