ionic5 新建组件提示 ‘app-footer‘ is not a known element

新建footer组件在home组件里调用的时候提示：
'app-footer' is not a known element: 1. If 'app-footer' is an Angular component, then verify that it is part of this module. 2. If 'app-footer' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.

解决办法：

1.将 FooterPageModule 里的 RouterModule 去掉，如果不是将footer组件做为单独的页面的话

2.加个 export 导出 footer 的 page：exports: [FooterPage]

3.home.module.ts导入 FooterPageModule

footer.module.ts

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { IonicModule } from '@ionic/angular';
import { FormsModule } from '@angular/forms';
import { FooterPage } from './footer.page';

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    IonicModule,
  ],
  declarations: [FooterPage],
  exports: [FooterPage]
})
export class FooterPageModule { }

home.module.ts

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { IonicModule } from '@ionic/angular';
import { FormsModule } from '@angular/forms';
import { HomePage } from './home.page';
import { RouterModule } from '@angular/router';
import { HeaderPageModule } from '../header/header.module';
import { FooterPageModule } from '../footer/footer.module';

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    IonicModule,
    HeaderPageModule,
    FooterPageModule,
    RouterModule.forChild([
      {
        path: '',
        component: HomePage,
      }
    ])
  ],
  declarations: [HomePage]
})
export class HomePageModule {}