Can't bind to 'routerLink' since it isn't a known property

问题

Recently, I have started playing with angular 2. It's awesome so far. So, i have started a demo personal project for the sake of learning using angular-cli.

With the basic routing setup, I now want to navigate to some routes from header, but since my header is a parent to the router-outlet, I receive this error.

app.component.html

<app-header></app-header> // Trying to navigate from this component
    <router-outlet></router-outlet>
<app-footer></app-footer>

header.component.html

  <a [routerLink]="['/signin']">Sign in</a>

Now I understand partially I guess that since that component is a wrapper around router-outlet it would not be possible this way to access router. So, is there a possibility to access navigation from outside for a scenario like this?

I would be really happy to add any more information if needed. Thank you in advance.

Update

1- My package.json already has the stable @angular/router 3.3.1 version. 2- In my main app module, I have imported the routing-module. Please see below.

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { AlertModule  } from 'ng2-bootstrap';
import { LayoutModule } from './layout/layout.module';
import { UsersModule } from './users/users.module';
import { AppRoutingModule } from  './app-routing.module';
import { AppComponent } from './app.component';
import { PageNotFoundComponent } from './shared/components/not-found.component';

@NgModule({
  declarations: [
    AppComponent,
    PageNotFoundComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    AlertModule.forRoot(),
    LayoutModule,
    UsersModule,
    AppRoutingModule  --> This is the routing module. 
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app-routing.module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { SigninComponent } from './users/signin/signin.component';
import { PageNotFoundComponent } from './shared/components/not-found.component';

const routes: Routes = [
{ path: '**', component: PageNotFoundComponent }
];

@NgModule({
    imports: [RouterModule.forRoot(routes)],
    exports: [RouterModule]
})

export class AppRoutingModule {}

The route I am trying to access is delegated from another module that is the UsersModule

user-routing.module.ts

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { SigninComponent } from './signin/signin.component';

const usersRoutes: Routes = [
  { path: 'signin',  component: SigninComponent }
];
@NgModule({
  imports: [
    RouterModule.forChild(usersRoutes)
  ],
  exports: [
    RouterModule
  ]
})

export class UsersRoutingModule { }

While I am trying to navigate from a component that is part of the Layout module, but has no notion of the router module. Is that what is causing the error.

Layout.module.ts

import { NgModule } from '@angular/core';
import { HeaderComponent } from './header/header.component';
import { FooterComponent } from './footer/footer.component';

@NgModule({
  declarations: [HeaderComponent, FooterComponent],
  exports: [HeaderComponent, FooterComponent]
})
export class LayoutModule{}

I am trying to navigate from the HeaderComponent. I would be happy to provide more information if needed.

回答1:

You need to add RouterModule to imports of every @NgModule() where components use any component or directive from (in this case routerLink and <router-outlet>.

declarations: [] is to make components, directives, pipes, known inside the current module.

exports: [] is to make components, directives, pipes, available to importing modules. What is added to declarations only is private to the module. exports makes them public.

回答2:

You are missing either the inclusion of the route package, or including the router module in your main app module.

Make sure your package.config has this:

"@angular/router": "^3.3.1"

Then in your app.module import the router and configure the routes:

import { RouterModule } from '@angular/router';

imports: [
        RouterModule.forRoot([
            {path: '', component: DashboardComponent},
            {path: 'dashboard', component: DashboardComponent}
        ])
    ],

Update:

Move the AppRoutingModule to be first in the imports:

imports: [
    AppRoutingModule.
    BrowserModule,
    FormsModule,
    HttpModule,
    AlertModule.forRoot(), // What is this?
    LayoutModule,
    UsersModule
  ],

回答3:

I'll add another case where I was getting the same error but just being a dummy. I had added [routerLinkActiveOptions]="{exact: true}" without yet adding routerLinkActive="active".

My incorrect code was

<a class="nav-link active" routerLink="/dashboard" [routerLinkActiveOptions]="{exact: true}">
  Home
</a>

when it should have been

<a class="nav-link active" routerLink="/dashboard" routerLinkActive="active" [routerLinkActiveOptions]="{exact: true}">
  Home
</a>

Without having routerLinkActive, you can't have routerLinkActiveOptions.

来源：https://stackoverflow.com/questions/42035387/cant-bind-to-routerlink-since-it-isnt-a-known-property