Angular 5 从共享模块注入组件时出现静态注入器错误

Question

这是我的组件文件。我正在尝试使用 ng-bootstraps modal 创建一个可重用的模态组件。当我尝试从共享模块导入以下组件时出现静态注入器错误。我查看了许多其他资源，但无法弄清楚我的实现有什么问题。

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

    import {NgbModal, ModalDismissReasons} from '@ng-bootstrap/ng-bootstrap';

    @Component({
      selector: 'ngbd-modal-basic',
      templateUrl: './customM.component.html'
    })
    export class CustomModalComponent {
      closeResult: string;

      constructor(private modalService: NgbModal) {}

      open(content) {
        this.modalService.open(content).result.then((result) => {
          this.closeResult = `Closed with: ${result}`;
        }, (reason) => {
          this.closeResult = `Dismissed ${this.getDismissReason(reason)}`;
        });
      }

      private getDismissReason(reason: any): string {
        if (reason === ModalDismissReasons.ESC) {
          return 'by pressing ESC';
        } else if (reason === ModalDismissReasons.BACKDROP_CLICK) {
          return 'by clicking on a backdrop';
        } else {
          return  `with: ${reason}`;
        }
      }
    }

下面是正在声明和导出 ModalComponent 的 SharedModule。

import { NgModule  } from '@angular/core';
import { CommonModule } from '@angular/common';

import { LoaderComponent } from './loader/loader.component';

import * as Shared from './index'; 

@NgModule({
  imports: [
    CommonModule
  ],
  declarations: [
    LoaderComponent,
    Shared.CustomModalComponent
  ],
  exports: [
    LoaderComponent,
    Shared.CustomModalComponent
  ],
  providers: []
})
export class SharedModule { 
  // static forRoot() : ModuleWithProviders {
  //   return {
  //     ngModule: SharedModule,
  //     providers: [ WebsocketService ]
  //   }
  // }
}

只要在构造函数中声明静态注入器错误，就会在此处抛出。

import { Component, OnInit } from '@angular/core';
import { Router } from '@angular/router';
import { FormGroup, FormBuilder, Validators } from '@angular/forms';
import { finalize } from 'rxjs/operators';

import { environment } from '@env/environment';
import { Logger, I18nService, AuthenticationService } from '@app/core';

import { CustomModalComponent } from '../shared/_directives/custom-modal/customM.component';

const log = new Logger('Login');

@Component({
  selector: 'app-login',
  templateUrl: './login.component.html',
  styleUrls: ['./login.component.scss']
})
export class LoginComponent implements OnInit {

  version: string = environment.version;
  error: string;
  loginForm: FormGroup;
  isLoading = false;

  constructor(private router: Router,
              private formBuilder: FormBuilder,
              private i18nService: I18nService,
              private authenticationService: AuthenticationService,
              private c: CustomModalComponent) {
    this.createForm();
  }

主App.module文件

import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule, NoopAnimationsModule } from '@angular/platform-browser/animations';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { TranslateModule } from '@ngx-translate/core';
import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
import { NgxChartsModule } from '@swimlane/ngx-charts';
import { CoreModule } from '@app/core';
import { SharedModule } from '@app/shared';
import { HomeModule } from './home/home.module';
import { AboutModule } from './about/about.module';
import { LoginModule } from './login/login.module';
import { AppComponent } from './app.component';
import { AppRoutingModule } from './app-routing.module';

@NgModule({
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    NoopAnimationsModule,
    FormsModule,
    HttpModule,
    TranslateModule.forRoot(),
    NgbModule.forRoot(),
    CoreModule,
    SharedModule,
    HomeModule,
    AboutModule,
    LoginModule,
    NgxChartsModule,
    AppRoutingModule
  ],
  declarations: [AppComponent],
  providers: [ ],
  bootstrap: [AppComponent]
})
export class AppModule { }

Answer 1

你必须考虑两件事：

您的应用只有一个根注入器，其中包含您应用中任何模块（包括 AppModule）的@NgModule.providers 数组中指定的所有提供程序。每个组件都有自己的注入器（根注入器的子注入器），其中包含在组件的@Component.providers 数组中声明的提供程序。当 angular 想要解析服务 (MainService) 的依赖项 (RightClickService) 时，他会在包含所有 NgModules 提供者的根注入器中查找它。

当angular想要解决组件（RightClickComponent）的依赖关系（RightClickService）时，他会在组件注入器中寻找它，如果找不到，他会在父组件注入器中寻找，如果找不到，他会这样做直到他到达根注入器，如果没有找到，将抛出错误。

所以，我遇到了同样的问题，这很烦人，但当我在组件模块文件中定义依赖项时，问题终于得到解决。

PS：解释自

Angular 5 从共享模块注入组件时出现静态注入器错误

Angular 5 Static Injector error when injecting a component from a sharedmodule

typescript

angular5

angular-components

ng-modules