Subject 的变体，仅在完成时才发出值。完成后，它将向所有观察者发出其最新价值。

class AsyncSubject<T> extends Subject {
  _subscribe(subscriber: Subscriber<any>): Subscription
  next(value: T): void
  error(error: any): void
  complete(): void

 
  // inherited from index/Subject
  static create: Function
  constructor()
  observers: Observer<T>[]
  closed: false
  isStopped: false
  hasError: false
  thrownError: any
  lift<R>(operator: Operator<T, R>): Observable<R>
  next(value?: T)
  error(err: any)
  complete()
  unsubscribe()
  _trySubscribe(subscriber: Subscriber<T>): TeardownLogic
  _subscribe(subscriber: Subscriber<T>): Subscription
  asObservable(): Observable<T>

 
  // inherited from index/Observable
  static create: Function
  static if: typeof iif
  static throw: typeof throwError
  constructor(subscribe?: (this: Observable<T>, subscriber: Subscriber<T>) => TeardownLogic)
  _isScalar: boolean
  source: Observable<any>
  operator: Operator<any, T>
  lift<R>(operator: Operator<T, R>): Observable<R>
  subscribe(observerOrNext?: NextObserver<T> | ErrorObserver<T> | CompletionObserver<T> | ((value: T) => void), error?: (error: any) => void, complete?: () => void): Subscription
  _trySubscribe(sink: Subscriber<T>): TeardownLogic
  forEach(next: (value: T) => void, promiseCtor?: PromiseConstructorLike): Promise<void>
  pipe(...operations: OperatorFunction<any, any>[]): Observable<any>
  toPromise(promiseCtor?: PromiseConstructorLike): Promise<T>
}

方法

订阅（） _subscribe(subscriber: Subscriber<any>): Subscription

Returns Subscription

下一个（） next(value: T): void

Returns void

错误（）

Returnsvoid