我正在使用Angular 7并使用observable调用简单服务
import { Injectable } from '@angular/core';
import { Http,Headers} from '@angular/http';
import { Observable } from 'rxjs';
@Injectable({
providedIn: 'root'
})
export class AuthService {
constructor(private http:Http) { }
registerUser(user):Observable<any>{
let headers = new Headers();
headers.append('Content-Type','application/json');
return this.http.post('http://localhost:8888/users/register',user,{headers:headers});
}
}
虽然编译代码是好的,但当它命中注册url和组件然后它给出错误
ERROR Error: "[object Object]"
resolvePromise http://localhost:4200/polyfills.js:3159:31
resolvePromise http://localhost:4200/polyfills.js:3116:17
scheduleResolveOrReject http://localhost:4200/polyfills.js:3218:17
invokeTask http://localhost:4200/polyfills.js:2766:17
onInvokeTask http://localhost:4200/vendor.js:72221:24
invokeTask http://localhost:4200/polyfills.js:2765:17
runTask http://localhost:4200/polyfills.js:2533:28
drainMicroTaskQueue http://localhost:4200/polyfills.js:2940:25
vendor.js:70671:5
defaultErrorLogger
http://localhost:4200/vendor.js:70671:5
./node_modules/@angular/core/fesm5/core.js/ErrorHandler.prototype.handleError
http://localhost:4200/vendor.js:70719:9
next
http://localhost:4200/vendor.js:72698:111
./node_modules/@angular/core/fesm5/core.js/EventEmitter.prototype.subscribe/schedulerFn<
http://localhost:4200/vendor.js:68245:36
./node_modules/rxjs/_esm5/internal/Subscriber.js/SafeSubscriber.prototype.__tryOrUnsub
http://localhost:4200/vendor.js:141501:13
./node_modules/rxjs/_esm5/internal/Subscriber.js/SafeSubscriber.prototype.next
http://localhost:4200/vendor.js:141439:17
./node_modules/rxjs/_esm5/internal/Subscriber.js/Subscriber.prototype._next
http://localhost:4200/vendor.js:141382:9
./node_modules/rxjs/_esm5/internal/Subscriber.js/Subscriber.prototype.next
http://localhost:4200/vendor.js:141359:13
./node_modules/rxjs/_esm5/internal/Subject.js/Subject.prototype.next
http://localhost:4200/vendor.js:141124:25
./node_modules/@angular/core/fesm5/core.js/EventEmitter.prototype.emit
http://localhost:4200/vendor.js:68229:54
onHandleError/<
http://localhost:4200/vendor.js:72252:57
./node_modules/zone.js/dist/zone.js/</ZoneDelegate.prototype.invoke
zone.js:388
./node_modules/zone.js/dist/zone.js/</Zone.prototype.run
zone.js:138
./node_modules/@angular/core/fesm5/core.js/NgZone.prototype.runOutsideAngular
http://localhost:4200/vendor.js:72189:16
onHandleError
http://localhost:4200/vendor.js:72252:13
./node_modules/zone.js/dist/zone.js/</ZoneDelegate.prototype.handleError
zone.js:392
./node_modules/zone.js/dist/zone.js/</Zone.prototype.runGuarded
zone.js:154
_loop_1
zone.js:677
./node_modules/zone.js/dist/zone.js/</</api.microtaskDrainDone
zone.js:686
drainMicroTaskQueu
e
zone.js:602
如果我从’../../services/auth.service’中删除组件// import {AuthService}中的服务类;然后代码运行没有错误.
尝试返回简单的返回用户,但仍然出现错误.
也尝试了没有观察到的回归.
你能帮助我做错的地方吗？
解决方法
自Angular 5以来,Http的使用已被弃用.因此它不会在Angular 7中提供.
你应该使用HttpClient而不是Http.此外,默认情况下会添加Content-Type标头.所以你不需要明确地添加它.
最后,http.post已经返回一个Observable.所以你不需要把它包装成一个
import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
@Injectable({
providedIn: 'root'
})
export class AuthService {
constructor(private http: HttpClient) {}
registerUser(user): Observable <any> {
return this.http.post('http://localhost:8888/users/register',user);
}
}
您还必须将HttpClientModule添加到AppModule的imports数组中：
import { HttpClientModule } from '@angular/common/http';
@NgModule({
...,imports: [...,HttpClientModule,...]
...
})
然后在你的组件中：
constructor(private authService: AuthService) {}
...
const user = ...
this.authService.registerUser(user)
.subscribe(response => console.log(response));
...
