EventTarget 类型

定义于: https://github.com/cocos-creator/engine/blob/de46973d0b5edcff4f973186ce89752080cb6b7c/cocos2d/core/event/event-target.js:100

模块: cc 父模块: cc

事件目标是事件触发时，分派的事件对象，Node 是最常见的事件目标， 但是其他对象也可以是事件目标。

索引

方法

• on 注册事件目标的特定事件类型回调。
• off 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。
• targetOff 在当前 EventTarget 上删除指定目标（target 参数）注册的所有事件监听器。
• once 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。
• dispatchEvent 分发事件到事件流中。
• emit 该对象直接发送事件， 这种方法不会对事件传播到任何其他对象。

Details

方法

on

注册事件目标的特定事件类型回调。

参数列表

• type String A string representing the event type to listen for.
• callback Function The callback that will be invoked when the event is dispatched.

                         The callback is ignored if it is a duplicate (the callbacks are unique).
  

  • event Event event
• target Object The target (this object) to invoke the callback, can be null
• useCapture Boolean When set to true, the capture argument prevents callback

                         from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE.
                         When false, callback will NOT be invoked when event's eventPhase attribute value is CAPTURING_PHASE.
                         Either way, callback will be invoked when event's eventPhase attribute value is AT_TARGET.
  

示例

node.on(cc.Node.EventType.TOUCH_END, function (event) {
    cc.log("this is callback");
}, node);

off

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。

参数列表

• type String A string representing the event type being removed.
• callback Function The callback to remove.
• target Object The target (this object) to invoke the callback, if it's not given, only callback without target will be removed
• useCapture Boolean Specifies whether the callback being removed was registered as a capturing callback or not.

                         If not specified, useCapture defaults to false. If a callback was registered twice,
                         one with capture and one without, each must be removed separately. Removal of a capturing callback
                         does not affect a non-capturing version of the same listener, and vice versa.
  

示例

// register touchEnd eventListener
var touchEnd = node.on(cc.Node.EventType.TOUCH_END, function (event) {
    cc.log("this is callback");
}, node);
// remove touch end event listener
node.off(cc.Node.EventType.TOUCH_END, touchEnd, node);
// remove all touch end event listeners
node.off(cc.Node.EventType.TOUCH_END);

targetOff

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。

参数列表

• target Object The target to be searched for all related listeners

once

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。

参数列表

• type String A string representing the event type to listen for.
• callback Function The callback that will be invoked when the event is dispatched.

                         The callback is ignored if it is a duplicate (the callbacks are unique).
  

  • event Event event
• target Object The target (this object) to invoke the callback, can be null
• useCapture Boolean When set to true, the capture argument prevents callback

                         from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE.
                         When false, callback will NOT be invoked when event's eventPhase attribute value is CAPTURING_PHASE.
                         Either way, callback will be invoked when event's eventPhase attribute value is AT_TARGET.
  

示例

node.once(cc.Node.EventType.TOUCH_END, function (event) {
    cc.log("this is callback");
}, node);

dispatchEvent

分发事件到事件流中。

参数列表

• event Event The Event object that is dispatched into the event flow

emit

该对象直接发送事件， 这种方法不会对事件传播到任何其他对象。

参数列表

• message String the message to send
• detail Any whatever argument the message needs