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CustomEvent - Web API 接口参考编辑

CustomEvent 事件是由程序创建的，可以有任意自定义功能的事件。

Note: 此特性在 Web Worker 中可用。

属性

CustomEvent.detail 只读任何时间初始化时传入的数据

此接口从父接口继承属性, Event:

Event.bubbles Read only: A boolean indicating whether or not the event bubbles up through the DOM.
Event.cancelBubble: A historical alias to Event.stopPropagation(). Setting its value to true before returning from an event handler prevents propagation of the event.
Event.cancelable Read only: A boolean indicating whether the event is cancelable.
Event.composed Read only: A boolean indicating whether or not the event can bubble across the boundary between the shadow DOM and the regular DOM.
Event.currentTarget Read only: A reference to the currently registered target for the event. This is the object to which the event is currently slated to be sent. It's possible this has been changed along the way through retargeting.
Event.deepPath: An Array of DOM Nodes through which the event has bubbled.
Event.defaultPrevented Read only: Indicates whether or not the call to event.preventDefault() canceled the event.
Event.eventPhase Read only: Indicates which phase of the event flow is being processed.
Event.explicitOriginalTarget Read only: The explicit original target of the event (Mozilla-specific.)
Event.originalTarget Read only: The original target of the event, before any retargetings. (Mozilla-specific.)
Event.returnValue: A historical property introduced by Internet Explorer and eventually adopted into the DOM specification in order to ensure existing sites continue to work. Ideally, you should try to use Event.preventDefault() and Event.defaultPrevented instead, but you can use returnValue if you choose to do so.
Event.srcElement: A non-standard alias (from old versions of Microsoft Internet Explorer) for Event.target. Some other browsers are starting to support it for web compatibility purposes.
Event.target Read only: A reference to the target to which the event was originally dispatched.
Event.timeStamp Read only: The time at which the event was created (in milliseconds). By specification, this value is time since epoch—but in reality, browsers' definitions vary. In addition, work is underway to change this to be a DOMHighResTimeStamp instead.
Event.type Read only: The name of the event. Case-insensitive.
Event.isTrusted Read only: Indicates whether or not the event was initiated by the browser (after a user click, for instance) or by a script (using an event creation method, like Event.initEvent).

Deprecated properties

Event.scoped Read only: A Boolean indicating whether the given event will bubble across through the shadow root into the standard DOM. Use composed instead.

方法

CustomEvent.initCustomEvent(): 初始化一个CustomEvent 对象.如果事件已经被触发,这个方法不起任何作用.

此接口从父接口继承方法, Event:

Event.composedPath(): Returns the event’s path (objects on which listeners will be invoked). This does not include nodes in shadow trees if the shadow root was created with its ShadowRoot.mode closed.

Event.preventDefault(): Cancels the event (if it is cancelable).
Event.stopImmediatePropagation(): For this particular event, prevent all other listeners from being called. This includes listeners attached to the same element as well as those attached to elements that will be traversed later (during the capture phase, for instance).
Event.stopPropagation(): Stops the propagation of events further along in the DOM.

Deprecated methods

Event.createEvent(): Creates a new event, which must then be initialized by calling its initEvent() method.
Event.initEvent(): Initializes the value of an Event created. If the event has already been dispatched, this method does nothing.
Event.getPreventDefault(): Returns the value of Event.defaultPrevented.
Event.preventBubble(): Prevents the event from bubbling. Use event.stopPropagation instead.
Event.preventCapture(): Prevents the event from bubbling. Use event.stopPropagation instead.

方法概述

void initCustomEvent(in DOMString type, in boolean canBubble, in boolean cancelable, in any detail);

属性

Attribute	Type	Description
`detail`	`any`	当事件初始化时传递的数据

方法

initCustomEvent()

初始化一个自定义事件的方式和初始化一个标准DOM事件的方式非常相似.

void initCustomEvent(
  in DOMString type,
  in boolean canBubble,
  in boolean cancelable,
  in any detail
);

参数

type: 事件的类型名称.
canBubble: 一个布尔值,表明该事件是否会冒泡.
cancelable: 一个布尔值,表明该事件是否可以被取消.
detail: 当事件初始化时传递的数据.

构造函数

DOM4 规范添加了对 CustomEvent 构造函数的支持.

CustomEvent(
  DOMString type,
  optional CustomEventInit eventInitDict
)

参数

type: 事件的类型名称.
eventInitDict: 一个对象,提供了事件的配置信息.查看CustomEventInit了解更多详情.

CustomEventInit

bubbles: 一个布尔值,表明该事件是否会冒泡.
cancelable: 一个布尔值,表明该事件是否可以被取消.
detail: 当事件初始化时传递的数据.

CustomEvent用法示例

// 添加一个适当的事件监听器
obj.addEventListener("cat", function(e) { process(e.detail) })

// 创建并分发事件
var event = new CustomEvent("cat", {"detail":{"hazcheeseburger":true}})
obj.dispatchEvent(event)

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.