Angular arrow函数的角度2可观测单值
我的组件中有以下代码:Angular arrow函数的角度2可观测单值,angular,observable,arrow-functions,Angular,Observable,Arrow Functions,我的组件中有以下代码: private katalog : Katalog; private allKatalogs : Katalog[] = []; constructor(private adminService : AdminService) { } ngOnInit() { this.adminService.get_kataloge().subscribe((items : Katalog[]) => this.allKatalogs = items
private katalog : Katalog;
private allKatalogs : Katalog[] = [];
constructor(private adminService : AdminService) { }
ngOnInit() {
this.adminService.get_kataloge().subscribe((items : Katalog[]) => this.allKatalogs = items);
this.adminService.get_kataloge().subscribe((items : Katalog[]) => this.katalog = items[0]);
}
showObject() {
console.log(this.katalog); // this returns undefined
console.log(this.allKatalogs); // this returns [Object, Object, Object, Object, Object]
}
为什么这个.katalog
没有定义
服务内容如下:
get_kataloge() : Observable<Katalog[]> { return this.kataloge.asObservable(); }
模板html
<p (click)="showObject()">show object</p>
显示对象
什么类型的:Katalog;?您可以显示katalog类或接口吗?调用的
showObject()
在哪里?另外,您应该将showObject()
放在ngOnInit()
内或ngAfterViewInit()
中,整个问题可能是调用的异步性质
<p (click)="showObject()">show object</p>