我正面临这个非常普遍的问题。试图向组件注入服务。但是得到这个 Can't resolve all parameters for VehicleComponent 错误。不知道为什么会这样。尝试将@Inject 放在依赖参数上,尝试在其他模块中提供,在组件本身中提供但没有用。试图注入 NavigationControllerService。顺便说一句,我可以将服务注入我的应用程序组件。
这是我的应用程序模块。这里提供服务
import { AppComponent } from "./app.component";
import { AppRoutingModule } from './app.routing.module';
import HomeComponent from './ngComponents/home/home.component';
import { VehicleModule } from './ngComponents/vehicle/vehicle.module';
import { DataTableComponent } from './uiComponents/datatable/datatable.component';
import { AppConfigService } from './services/appConfig.service';
import { VehicleHTTPService } from './services/http/vehicleHTTP.service';
import { HttpClientModule } from '@angular/common/http';
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { CommonModule } from "@angular/common";
import { TabComponent } from "./uiComponents/tab/tab.component";
import { NavigationControllerService } from "./services/navigation/navigationController.service";
@NgModule({
declarations: [AppComponent, HomeComponent],
imports: [BrowserModule, CommonModule, AppRoutingModule, HttpClientModule, VehicleModule],
providers: [AppConfigService, VehicleHTTPService, NavigationControllerService],
bootstrap: [AppComponent],
entryComponents: [TabComponent]
})
export class AppModule {
}
车辆模块
import { NgModule } from "@angular/core";
import { VehicleRoutingModule } from "./vehicle.routing.module";
import { VehicleListComponent } from "./vehicleList/vehicleList.component";
import { VehicleComponent } from "./vehicle.component";
import { VehicleFormComponent } from "./vehicleForm/vehicleForm.component";
import { VehicleHTTPService } from "../../services/http/vehicleHTTP.service";
import { HttpClientModule } from "@angular/common/http";
import { DataTableComponent } from "../../uiComponents/datatable/datatable.component";
import { CommonModule } from "@angular/common";
@NgModule({
imports: [CommonModule, VehicleRoutingModule],
declarations: [VehicleComponent, VehicleListComponent, VehicleFormComponent, DataTableComponent],
})
export class VehicleModule {
}
和我试图注入的车辆组件。
import { NavigationControllerService } from "../../services/navigation/navigationController.service";
import { Component } from "@angular/core";
import { ActivatedRoute } from "@angular/router";
@Component({
selector: "vehicle",
templateUrl: 'vehicle.component.html',
styleUrls: ['vehicle.component.css']
})
export class VehicleComponent {
constructor(public navigationControllerService: NavigationControllerService) {
}
}
您可以从这里访问完整项目https://github.com/aliemre1990/dokuzisik-mean 感谢您的帮助。
编辑:我认为问题是由 NavigationControllerService 引起的。我创建了一个空的服务类并在我的 AppModule 上提供它,以使相同的服务实例在整个应用程序中可用。在车辆组件上,此空服务按预期注入。但在我看来,navigationcontrollerservice 再次无法创建,也无法注入。我应该调查为什么它不能创建导航控制器服务的实例。也许它关于其构造函数中提供的依赖项。我也在提供我的导航控制器服务。
import { EventEmitter, Injectable, Injector, ApplicationRef, ComponentFactoryResolver, EmbeddedViewRef, ComponentRef } from "@angular/core";
import { TabComponent } from "../../uiComponents/tab/tab.component";
import { VehicleComponent } from "../../ngComponents/vehicle/vehicle.component";
import { VehicleFormComponent } from "../../ngComponents/vehicle/vehicleForm/vehicleForm.component";
@Injectable()
export class NavigationControllerService {
readonly tabContentContainerClass = "tab-content-container";
readonly tabNavigationContainerClass = "tab-navigation-container";
public openComponents: Array<ComponentRef<TabComponent>>;
constructor(private componentFactoryResolver: ComponentFactoryResolver,
private appRef: ApplicationRef,
private injector: Injector) {
this.openComponents = [];
}
public closeCurrent() {
}
private deActiveAll() {
this.openComponents.forEach(x => x.instance.active = false);
}
private navigate(component: any) {
var compRef = this.openComponents.find(x => x.instance.component === component);
if (compRef) {
this.deActiveAll();
compRef.instance.active = true;
}
else {
this.add(VehicleComponent);
}
var compRef = this.openComponents.find(x => x.instance.component === component);
switch (compRef.instance.component) {
case VehicleComponent:
compRef.instance.title = "Araç Listesi";
break;
default:
compRef.instance.title = "Default";
break;
}
}
private add(component: any) {
const componentRef = this.componentFactoryResolver
.resolveComponentFactory(TabComponent)
.create(this.injector);
// 2. Attach component to the appRef so that it's inside the ng component tree
this.appRef.attachView(componentRef.hostView);
// 3. Get DOM element from component
const domElem = (componentRef.hostView as EmbeddedViewRef<any>)
.rootNodes[0] as HTMLElement;
// 4. Append DOM element to the body
document.querySelector("." + this.tabContentContainerClass).appendChild(domElem);
if (componentRef.instance.navigateComponent)
componentRef.instance.navigateComponent(component);
componentRef.instance.active = true;
this.openComponents.push(componentRef);
}
public navigateVehicleComponent() {
this.navigate(VehicleComponent);
}
public navigateVehicleFormComponent() {
this.navigate(VehicleFormComponent);
}
}
再次编辑:我将我的项目转移到 angular-cli,它给出了循环依赖警告。我的 vehicleCompnent 依赖于 navigationController 并且 navigationController 使用了 vehicleComponent。从导航控制器中删除车辆组件解决了这个问题。