typescript 角度 - 输出事件发射器+检查是否观察到

Posted 2021-05-20

// Output 'help' of type EventEmitter emits an event to the parent component (help)="myFunc()"
@Output()
help: EventEmitter<void> = new EventEmitter<void>()

helpClicked() {
  this.help.emit()
}

ngOnInit() {
  // check if the event is handled (or observed)
  this.showHelpDeskLink = this.help.observers.length > 0
}