Angular 2在订阅中执行函数

Question

我有ngOnInit 2 vars可用项目和标题，项目用于视图，我想“执行”index.html中的setSeoTitle（）函数，我该如何实现？

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

 $conn = mysqli_connect($servername, $username, $password, $dbname);
 ^^^^^