问Ionic3管道‘翻译’找不到

EN

Error: Uncaught (in promise): Error: Template parse errors:
The pipe 'translate' could not be found ("
<ion-content padding>
<h2>{{[ERROR ->]"HELLO" | translate }}</h2>
</ion-content>
"): ng:///AdminPannelPageModule/AdminPannelPage.html@11:8

"@ngx-translate/core": "^9.1.1",
"@ngx-translate/http-loader": "^2.0.1",

npm install @ngx-translate/core @ngx-translate/http-loader --save

<h2>{{"HELLO" | translate }}</h2>

assets/i18n/en.json

{
"HELLO": "hello"
}

assets/i18n/it.json

{
"HELLO": "ciao"
}

import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { HttpClientModule, HttpClient } from '@angular/common/http';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

export function setTranslateLoader(http: HttpClient) {
return new TranslateHttpLoader(http, './assets/i18n/', '.json');
}


@NgModule({
imports: [
HttpClientModule,
IonicModule.forRoot(MyApp),
TranslateModule.forRoot({
  loader: {
    provide: TranslateLoader,
    useFactory: (setTranslateLoader),
    deps: [HttpClient]
  }
}),
],

constructor(..., translate: TranslateService) {
     translate.setDefaultLang('en');
     ...
}