角度http post通过服务将数据返回到组件

这肯定会帮助您对web api进行后期调用

https://dheerajsroy.wixsite.com/dheerajkumar/single-post/2017/09/07/How-to-make-Post-Call-in-Angular-2

为您服务

 return this.http.post(Url, JSON.stringify(data), requestOptions)
              .map((response: Response) => response.json())

在您的组件中

this.service.addSession(this.data).subscribe(
      data => { console.log(data) // Data which is returned by call
      },
      error => { console.log(error); // Error if any
      },
      ()=> // Here call is completed. If you wish to do something 
      // after call is completed(since this is an asynchronous call), this is the right place to do. ex: call another function
    )

Observable 从您的 addSession 没有 .subscribe

addSession() { 
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(this._url, JSON.stringify({}), options).catch(this.handleError);
}

subscribe 对于组件中的可观察值,当它完成调用时,将值分配给 myId

this.trackerFormService.addSession().subscribe(result => this.myId = result);