我不能在Angular中动态改变语言。

npm install @ngx-translate/core --save

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

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

@NgModule({
  imports: [
    BrowserModule,
    HttpClientModule,
    TranslateModule.forRoot({
      loader: {
        provide: TranslateLoader,
        useFactory: HttpLoaderFactory,
        deps: [HttpClient]
      }
    })
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

import { Component } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';

@Component({
  selector: 'app-root',
  template: `
    <h1>{{ 'HELLO' | translate }}</h1>
    <button (click)="changeLanguage('en')">English</button>
    <button (click)="changeLanguage('zh')">中文</button>
  `
})
export class AppComponent {
  constructor(private translate: TranslateService) {
    translate.setDefaultLang('en');
  }

  changeLanguage(lang: string) {
    this.translate.use(lang);
  }
}

{
  "HELLO": "Hello, World!"
}

{
  "HELLO": "你好，世界！"
}