派发一个指定事件，并传递需要的参数
event type
Arguments when the event triggered
检查指定事件是否已注册回调。
Event type
Callback function when event triggered
Callback callee
删除之前用同类型，回调，目标或 useCapture 注册的事件监听器，如果只传递 type，将会删除 type 类型的所有事件监听器。
A string representing the event type being removed.
The callback to remove.
The target (this object) to invoke the callback, if it's not given, only callback without target will be removed
注册事件目标的特定事件类型回调。这种类型的事件应该被 emit 触发。
A string representing the event type to listen for.
The callback that will be invoked when the event is dispatched. The callback is ignored if it is a duplicate (the callbacks are unique).
The target (this object) to invoke the callback, can be null
注册事件目标的特定事件类型回调，回调会在第一时间被触发后删除自身。
A string representing the event type to listen for.
The callback that will be invoked when the event is dispatched. The callback is ignored if it is a duplicate (the callbacks are unique).
The target (this object) to invoke the callback, can be null
移除在特定事件类型中注册的所有回调或在某个目标中注册的所有回调。
The event type or target with which the listeners will be removed
在当前 EventTarget 上删除指定目标（target 参数）注册的所有事件监听器。 这个函数无法删除当前 EventTarget 的所有事件监听器，也无法删除 target 参数所注册的所有事件监听器。 这个函数只能删除 target 参数在当前 EventTarget 上注册的所有事件监听器。
Generated using TypeDoc
!#en EventTarget is an object to which an event is dispatched when something has occurred. Entity are the most common event targets, but other objects can be event targets too.
Event targets are an important part of the Fireball event model. The event target serves as the focal point for how events flow through the scene graph. When an event such as a mouse click or a keypress occurs, Fireball dispatches an event object into the event flow from the root of the hierarchy. The event object then makes its way through the scene graph until it reaches the event target, at which point it begins its return trip through the scene graph. This round-trip journey to the event target is conceptually divided into three phases: