尝试使用服务在组件之间传递数据

Question

我正在使用服务在组件之间传递数据，我的组件如下所示

  constructor(private psService: ProjectShipmentService, private pdComp: ProjectDetailsComponent) {

  }
  ngOnInit() {
    this.psService.getTDate().subscribe(x => this.cachedResults = x);
    this.populateArrays();

我的服务在哪里

 constructor(private service: DataService, private pInfo: ProjectDetailsComponent) {

    this.rProjectNumber = this.pInfo.rProjectNumber;
    this.rProjectSO = this.pInfo.rSalesOrder;
    this.entityUrl = this.pInfo.entityUrl;
    this.tDate = service.get<ShipDateFilterModel[]>(this.entityUrl);
   }

即使 tDate 有数据，在 Component 中订阅它时也没有数据。当在 ngOnInIt 生命周期钩子上调用服务时，this.cachedResults 为空。我在这里错过了什么？

Answer 1

试试这个方法..

export class ProjectShipmentService {
  rProjectNumber;
  tDate: Observable<ShipDateFilterModel[]>;
  entityUrl;
  rProjectSO;

  constructor(private service: DataService, private pInfo: ProjectDetailsComponent) {
    this.rProjectNumber = this.pInfo.rProjectNumber;
    this.rProjectSO = this.pInfo.rSalesOrder;
    this.entityUrl = this.pInfo.entityUrl;
   }

getTDate(){
    return this.service.get<ShipDateFilterModel[]>(this.entityUrl);
}

在你的组件中。

  ngOnInit() {
    this.psService.getTDate.subscribe(x => this.cachedResults = x);
    this.populateArrays();
  }

希望这会有所帮助:)

Answer 2

你为什么不简单地在服务中创建一个方法，比如

getTDate(){
return this.service.get<ShipDateFilterModel[]>(this.entityUrl);
}

然后订阅你的组件

this.psService.getTDate().subscribe(x => this.cachedResults = x);