在Angular 7中使用NGRX并将令牌保存在本地存储中，可以按照以下步骤进行：

首先，确保已经安装了必要的包：

npm install @ngrx/store @ngrx/effects --save

然后，在你的应用程序中创建一个TokenService来处理令牌的存储和获取：

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class TokenService {
  private tokenKey = 'token';

  getToken(): string | null {
    return localStorage.getItem(this.tokenKey);
  }

  setToken(token: string): void {
    localStorage.setItem(this.tokenKey, token);
  }

  removeToken(): void {
    localStorage.removeItem(this.tokenKey);
  }
}

接下来，创建一个auth.reducer.ts文件来定义你的认证状态和操作：

import { createReducer, on } from '@ngrx/store';
import { loginSuccess, logout } from './auth.actions';

export interface AuthState {
  isAuthenticated: boolean;
  token: string | null;
}

export const initialState: AuthState = {
  isAuthenticated: false,
  token: null
};

export const authReducer = createReducer(
  initialState,
  on(loginSuccess, (state, { token }) => ({
    isAuthenticated: true,
    token: token
  })),
  on(logout, state => ({
    isAuthenticated: false,
    token: null
  }))
);

然后，在你的app.module.ts中设置NGRX Store和Effects：

import { StoreModule } from '@ngrx/store';
import { EffectsModule } from '@ngrx/effects';
import { authReducer } from './auth.reducer';
import { AuthEffects } from './auth.effects';

@NgModule({
  imports: [
    StoreModule.forRoot({ auth: authReducer }),
    EffectsModule.forRoot([AuthEffects])
  ],
  ...
})
export class AppModule { }

接下来，创建一个auth.actions.ts文件来定义你的认证操作：

import { createAction, props } from '@ngrx/store';

export const loginSuccess = createAction(
  '[Auth] Login Success',
  props<{ token: string }>()
);

export const logout = createAction('[Auth] Logout');

然后，创建一个auth.effects.ts文件来监听登录成功和登出操作：

import { Injectable } from '@angular/core';
import { Actions, createEffect, ofType } from '@ngrx/effects';
import { tap } from 'rxjs/operators';
import { TokenService } from './token.service';
import { loginSuccess, logout } from './auth.actions';

@Injectable()
export class AuthEffects {
  constructor(
    private actions$: Actions,
    private tokenService: TokenService
  ) {}

  loginSuccess$ = createEffect(
    () =>
      this.actions$.pipe(
        ofType(loginSuccess),
        tap(action => {
          this.tokenService.setToken(action.token);
        })
      ),
    { dispatch: false }
  );

  logout$ = createEffect(
    () =>
      this.actions$.pipe(
        ofType(logout),
        tap(() => {
          this.tokenService.removeToken();
        })
      ),
    { dispatch: false }
  );
}

最后，在你的登录组件中使用Store和Dispatch来处理登录操作：

import { Component } from '@angular/core';
import { Store } from '@ngrx/store';
import { loginSuccess } from './auth.actions';

@Component({
  selector: 'app-login',
  template: `...`
})
export class LoginComponent {
  constructor(private store: Store) {}

  login(): void {
    // 调用登录API获取令牌
    const token = 'your_token';

    this.store.dispatch(loginSuccess({ token }));
  }
}

这样，你就可以使用NGRX来管理认证状态，并将令牌保存在本地存储中了。