Angular 2中的subscribe中的execute函数

Question

我有ngOnInit 2 vars后可用的项目和标题，项目是为视图，我想"执行"setSeoTitle()函数在index.html，我怎么能实现这一点?

items = [];
title = [];
ngOnInit() {
    this.dataService.fetchData(this.slug)
        .subscribe(
        (data) => {
            this.items = data;
            this.title = data;
        }
    );
}
setSeoTitle(item){
    this.seoService.setTitle(item[0]['title']);
}

Answer 1

ngOnInit() {
    this.dataService.fetchData(this.slug)
        .subscribe(
        (data) => {
            this.items = data;
            this.title = data;
            this.setSeoTitle(this.items ); ///<<###< here 
        }
    );
}

Answer 2

ngOnInit() {
    this.dataService.fetchData(this.slug)
        .subscribe(
        (data) => {
            this.items = data;
            this.title = data;
            this.setSeoTitle(this.item);
        }
    );
}

Answer 3

ngOnInit() {
    this.dataService.fetchData(this.slug)
        .subscribe(
        (data) => {
            this.items = data;
            this.title = data;
            this.setSeoTitle(this.items);
        }
    );
}
setSeoTitle(items){
  if (items.length) {
    this.seoService.setTitle(items[0]['title']);
  }
}