从服务获取数据到我的组件

Question

我的服务是下面的 PortAllocationService

@Injectable({
  providedIn: 'root'
})
export class PortAllocationService {
  businessSwitchName: any;businessSwitchIp: any;businessSwitchportName: any;
  businessSwitchNodeId: any;routerName: any;routerIp: any;routerDetailsportName: any;
  routernodeID: any;aggSwitchName: any;aggSwitchPort: any;aggNodeIP: any;
  aggNodeId: any;serviceName: any;convertorDetails: any;handoffPort: any;qosLoopingPort: any;

  constructor(private http:HttpClient) { }

  portService(da){
    return this.http.post(url.portAllocationUrl , da).
    subscribe ((response:any) => {
      //Port Allocation response is mapped here
      console.log(response);
      // businessSwitchDetails 
      this.businessSwitchName = response.businessSwitchDetails.nodeName;
      this.businessSwitchIp = response.businessSwitchDetails.nodeIP;

     });

  }

和我的组件如下

export class WimaxFormComponent {
  data : any = {};
  btsIp :any; vCategory:any;nVlan:any;
 businessSwitchName:any;businessSwitchIp:any;businessSwitchportName:any;
 routerName:any;routerIp:any;aggSwitchName:any;aggSwitchPort:any;
 routerDetailsportName:any;routernodeID:any;aggNodeIP: any;aggNodeId: any;
 businessSwitchNodeId: any;serviceName: any;convertorDetails: any;
 handoffPort: any;qosLoopingPort: any;
 serviceId: any;serviceType: any;customerName: any;
 vReservedValue:boolean;cVlan: string;sVlan: any;
 path: string;

   constructor(
  private service: PortAllocationService){

  }

onChange(){

  let portAllocationData = {
  "serviceAttribute": {
    "serviceType": this.serviceType,
    "category": "category",
    "name": this.serviceId
  },
  "btsIp": this.btsIp
}
console.log(portAllocationData);

  this.service.portService(portAllocationData);
}

当我调用 onChange 函数时，调用的是服务，我们从服务器获得响应。但是我想访问从我的服务到组件的所有变量值，例如我在构造函数和 onChange 中都尝试过

this.businessSwitchName = service.businessSwitchName // 这是未定义的

请告诉我如何将变量值访问到组件中。

Answer 1

我不会在服务本身中订阅 API 调用，而是简单地返回由 http.post() 生成的 observable。然后将订阅移动到组件本身：

服务：

portService(da){ return this.http.post(url.portAllocationUrl , da) });

组件：

this.service.portService(portAllocationData).subscribe(response => {
    // Do stuff with the response here
});

---

但是，如果您真的想保留服务中的变量，我会将 API 调用放在服务的构造函数中，将服务中的字段更改为以下划线（或其他一些本地/私有标识符）开头然后为您希望能够访问的每个变量设置 get 方法。

服务：

get businessSwitchName() {
    return this._businessSwitchName;
}

组件：

this.service.businessSwitchName