Angular: Data callback never stops even when unsubscribe function is used

问题

I am trying to update the data from the api using this function

ngOnInit(){
        setInterval(()=>{
            this.getPhonebook();
        }, 1000);
    }



getPhonebook() {
    this.showPhonebook = this.beaconProvider.getPhoneBookDirectories().subscribe(data => {
        this.infos = data;
    }, (err) =>{
        console.log(err);
    })

}

and trying to destroy it using this:

 ionViewDidLeave(){
    this.showPhonebook.unsubscribe();   
 }

 ngOnDestroy(){
    this.showPhonebook.unsubscribe();   
 }

The Problem is when i try to destroy using ngDestroy or attach it to IonViewDidLeave() lifecycle the function still calls even when I'm already on a different page. So is there a way to achieve the auto update I desire angularly since my concern that given a large transaction the setInterval will cause errors.

回答1:

If you use setInterval in your component you will need to set clearInterval.

 myInterval: any;

 ngOnInit(){
    this.myInterval = setInterval(()=>{
        this.getPhonebook();
    }, 1000);
}



ngOnDestroy(){
    clearInterval(this.myInterval);
 }

来源：https://stackoverflow.com/questions/45363275/angular-data-callback-never-stops-even-when-unsubscribe-function-is-used