在Angular 7中，可以使用Ngrx和Rxjs 6来实现在惰性加载模块之间访问状态。以下是一个解决方法的示例代码：

首先，安装必需的包：

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

创建一个共享模块SharedModule：

shared.module.ts：

import { NgModule } from '@angular/core';
import { StoreModule } from '@ngrx/store';
import { EffectsModule } from '@ngrx/effects';

@NgModule({
  imports: [
    StoreModule.forRoot({}),
    EffectsModule.forRoot([])
  ],
  exports: [
    StoreModule,
    EffectsModule
  ]
})
export class SharedModule { }

在根模块AppModule中导入SharedModule：

app.module.ts：

import { NgModule } from '@angular/core';
import { SharedModule } from './shared/shared.module';

@NgModule({
  imports: [
    SharedModule
  ]
})
export class AppModule { }

创建一个状态模块StateModule：

state.module.ts：

import { NgModule } from '@angular/core';
import { StoreModule } from '@ngrx/store';
import { EffectsModule } from '@ngrx/effects';
import { featureReducer } from './state.reducer';
import { featureEffects } from './state.effects';

@NgModule({
  imports: [
    StoreModule.forFeature('feature', featureReducer),
    EffectsModule.forFeature(featureEffects)
  ]
})
export class StateModule { }

在惰性加载的模块LazyModule中导入StateModule：

lazy.module.ts：

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { StateModule } from './state/state.module';

@NgModule({
  imports: [
    CommonModule,
    StateModule
  ]
})
export class LazyModule { }

在状态模块StateModule中定义状态和效果：

state.reducer.ts：

import { createReducer, on } from '@ngrx/store';
import { initialState } from './state.state';
import { action1, action2 } from './state.actions';

export const featureReducer = createReducer(
  initialState,
  on(action1, (state, { payload }) => ({ ...state, prop1: payload })),
  on(action2, (state, { payload }) => ({ ...state, prop2: payload }))
);

state.actions.ts：

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

export const action1 = createAction('[Feature] Action 1', props<{ payload: any }>());
export const action2 = createAction('[Feature] Action 2', props<{ payload: any }>());

state.effects.ts：

import { Injectable } from '@angular/core';
import { Actions, createEffect, ofType } from '@ngrx/effects';
import { map } from 'rxjs/operators';
import { action1, action2 } from './state.actions';

@Injectable()
export class FeatureEffects {
  effect1$ = createEffect(() => this.actions$.pipe(
    ofType(action1),
    map(({ payload }) => action2({ payload: payload + ' transformed' }))
  ));

  constructor(private actions$: Actions) { }
}

现在，在LazyModule中可以通过使用NgRx的select函数来访问状态：

lazy.component.ts：

import { Component } from '@angular/core';
import { Store, select } from '@ngrx/store';
import { Observable } from 'rxjs';
import { prop1Selector } from './state/state.selectors';

@Component({
  selector: 'app-lazy',
  template: `
    
{{ prop1$ | async }}
    Dispatch Action
  `
})
export class LazyComponent {
  prop1$: Observable;

  constructor(private store: Store) {
    this.prop1$ = this.store.pipe(select(prop1Selector));
  }

  dispatchAction() {
    this.store.dispatch(action1({ payload: 'new value' }));
  }
}

state.selectors.ts：

import { createFeatureSelector, createSelector } from '@ngrx/store';
import { State } from './state.state';

export const selectFeatureState = createFeatureSelector('feature');
export const prop1Selector = createSelector(selectFeatureState, state => state.prop1);

现在，当在LazyModule中点击按钮时，将触发状态的更新，并相应地显示在LazyComponent中的{{ prop1$ | async }}中。