angular2 http请求过来的数据无法输出在模版

Question

item;//item={name:""}this.itemService.getItemByOem(this.oem).then((e)=>{          this.item=e['item'];           this.user=e['user'];          this.loader.dismiss();       })getItemByOem(oem): Promise<any[]> {        return this.http.get(this.baseUrl+"/"+oem,{headers: this.headers})                .toPromise()                .then(response => response.json())                .catch(this.handleError);     }模版中直接{{item.name}是报错的，js输出到控制台却有值，{{item | json}}里也是有name的除非我在开头直接先定义 item={name:""},这样才正常