在迁移到库时，Angular应用的状态可能会变得复杂。不同的库之间可能会共享一个状态，而这些库的状态也可能会影响到主应用程序本身的状态。为了解决状态管理的问题，我们可以使用 NgRx Redux 库。

以下是一个使用 NgRx 实现状态管理的示例：

1. 创建一个 State Interface

interface FeatureState {
  feature: FeatureState;
}

interface AppState {
  feature: FeatureState;
}

2. 创建一个 Action

import { Action } from '@ngrx/store';

export const ADD_TODO = '[Todo] Add Todo';

export class AddTodo implements Action {
  readonly type = ADD_TODO;

  constructor(public payload: any) {}
}

export type All = AddTodo;

3. 创建一个 Reducer

import { ADD_TODO, All } from './actions';

export const initialState = {
  todos: [] as any[]
};

export function reducer(state = initialState, action: All) {
  switch (action.type) {
    case ADD_TODO: {
      return {
        ...state, todos: [...state.todos, action.payload]
      };
    }

    default:
      return state;
  }
}

4. 连接至 AppModule

import { StoreModule } from '@ngrx/store';
import { reducer } from './reducers';

@NgModule({
  imports: [
    BrowserModule,
    StoreModule.forRoot({
      feature: reducer
    })
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

5. 在组件中访问 Store

import { Store } from '@ngrx/store';
import { AddTodo } from '../actions';

@Component({
  selector: 'app-todo-list',
  templateUrl: './todo-list.component.html',
  styleUrls: ['./todo-list.component.css']
})
export class TodoListComponent {
  todos: Observable;

  constructor(private store: Store) {
    this.todos = store.select(state => state.feature.todos);
  }

  addTodo() {
    this.store.dispatch(new AddTodo({
      id: Date.now(),
      text: 'New Todo'
    }));
  }
}

通过使用 NgRx Redux 库，我们可以更好地