如何在angular2中使用sharedModule？

Question

我有一个 angular2 组件，我想在多个模块之间共享。

所以我在 sharedModule 下面写了，

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import {GenericComponent} from './generic/generic.component';
@NgModule({
  imports:      [ BrowserModule ],
  declarations: [ GenericComponent ],
  exports:      [ GenericComponent ]
})
export class SharedModule { }

然后我将此 sharedModule 添加到多个模块中，如下所示：

app.module.ts

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import {SharedModule} from './shared.module';
import { AppComponent } from './app.component';
@NgModule({
  imports:      [ BrowserModule,SharedModule ],
  declarations: [ AppComponent ],
  exports:      [ AppComponent ],
  bootstrap: [AppComponent]
})
export class AppModule { }

我也类似地将 sharedModule 添加到 generic.module.ts 中，

generic.module.ts

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import {SharedModule} from './shared.module';
@NgModule({
  imports:      [ BrowserModule,SharedModule ],
  declarations: [ //.. here I have added all the components that generic uses ]
})
export class GenericModule { }

但是当我尝试在 generic.module.ts 的组件中使用通用组件时出现以下错误

模块“GenericModule”导入的意外值“undefined”

Answer 1

这是我的应用程序中使用共享模块的代码：

应用模块：

import { AboutModule } from './about/about.module';
import { SharedModule }   from './shared/shared.module';
import { Menubar, MenuItem } from 'primeng/primeng';

@NgModule({
    imports: [ BrowserModule, RouterModule.forRoot(appRoutes), SharedModule.forRoot(), 
               HomeModule ],
    declarations: [ AppComponent ],
    bootstrap: [ AppComponent ],
    providers: [ appRoutingProviders ]

}) 

export class AppModule {} 

首页模块：

import { SharedModule }   from '../shared/shared.module';
import {routing} from './home.routing'


@NgModule({
    imports: [ SharedModule, routing],
    declarations: [ HomeComponent, LoginComponent, RegisterComponent, VerifyComponent, 
                   VerifyEmailComponent, ForgotComponent, ForgotVerifyComponent, 
                   ChangeComponent, ChallengeComponent, LogoutComponent ], 
    bootstrap: [ HomeComponent ],
    providers: [ ]

}) 

export class HomeModule {} 

还有共享模块：

@NgModule({
  imports: [CommonModule, RouterModule, MenubarModule, GalleriaModule, InputTextModule, PanelModule, ButtonModule,
            DropdownModule, DialogModule, AccordionModule, CalendarModule, SelectButtonModule, CheckboxModule,
            ProgressBarModule, DataTableModule],
  declarations: [ ErrorMessagesComponent, FoodDashboardComponent ],
  exports: [ CommonModule, ReactiveFormsModule, HttpModule, RouterModule,
            MenubarModule, GalleriaModule, InputTextModule, PanelModule, ButtonModule, DropdownModule, DialogModule, AccordionModule, CalendarModule,
            SelectButtonModule, CheckboxModule, DataTableModule, ProgressBarModule, ErrorMessagesComponent, FoodDashboardComponent ]
})

export class SharedModule {
  //
  static forRoot(): ModuleWithProviders {
    return {
      ngModule: SharedModule,
      providers: [SettingsService, AppMenuService, AuthorizationService, LoginService, RegisterService, ThemeService, ValidationService,
        NutritionixService, AuthGuardService, CalculationService, ChallengeService ]
    };
  }
}

我的应用中有 20 多个模块，而且我在所有地方都使用共享模块。这工作得很好。希望对您有所帮助。

Answer 2

您不能在 featureModule 中使用 BroswerModule。因此，请确保您使用 CommonModule 而不是 BrowswerModule。

import { NgModule }      from '@angular/core';
import { CommonModule }        from '@angular/common';
import {SharedModule} from './shared.module';
@NgModule({
  imports:      [ CommonModule ,SharedModule ],
  declarations: [ //.. here I have added all the components that generic uses ],
  exports:      [ CommonModule]
})
export class GenericModule { }