实现
构造函数
new VTTCue()
new VTTCue(startTime, endTime, text, track): VTTCue
参数
startTime
number
endTime
number
text
string
track?
TextTrack | undefined
返回值
VTTCue属性
onenter
onenter:EventHandler
onexit
onexit:EventHandler
方法
addEventListener()
addEventListener(type:string, listener: EventListener, options?: boolean | AddEventListenerOptions | undefined): void
参数
type
string
listener
EventListeneroptions?
boolean | AddEventListenerOptions | undefined
dispatchEvent()
dispatchEvent(event: Event):boolean
参数
event
Event返回值
boolean
removeEventListener()
removeEventListener(type:string, listener: EventListener, options?: boolean | EventListenerOptions | undefined): void
参数
type
string
listener
EventListeneroptions?
boolean | EventListenerOptions | undefined
setTrack()
setTrack(track: TextTrack):void
不是常规的JS设置器

