这可以使用Rxjs库完成

this can be done using Rxjs library

在您的ts文件中

import "rxjs/Rx";


numberSubscription: Subscription;

getLocations(){
console.log("Get them all!"); 
const data = Observable.interval(10000).startWith(0); <= this is the time interval in ms at which you want check for change of data in database.
    this.numberSubscription = data.subscribe((number: number) => {
        this.API.getAllLocations().subscribe(result =>{
                    this.locations = result;
                    console.log(this.locations);
                    this.addLocationMarkers();
                    this.ref.markForCheck();
                });
    });
  }

希望这会有所帮助