Error: No provider for ChildrenOutletContexts [duplicate]

问题

I can not make use of angular/material with Angular 5 in any way. I followed this simple Tutorial, but whenever I insert some material tag in component HTML, the web page gets blank.

Angular CLI does not show any issues when using ng serve

Dependencies:

"dependencies": {
    "@angular/animations": "^5.0.5",
    "@angular/cdk": "^5.0.0-rc.2",
    "@angular/common": "^5.0.0",
    "@angular/compiler": "^5.0.0",
    "@angular/core": "^5.0.0",
    "@angular/forms": "^5.0.0",
    "@angular/http": "^5.0.0",
    "@angular/material": "^5.0.0-rc.2",
    "@angular/platform-browser": "^5.0.0",
    "@angular/platform-browser-dynamic": "^5.0.0",
    "@angular/router": "^5.0.0",
    "core-js": "^2.4.1",
    "hammerjs": "^2.0.8",
    "rxjs": "^5.5.2",
    "zone.js": "^0.8.14"
  },
  "devDependencies": {
    "@angular/cli": "1.5.5",
    "@angular/compiler-cli": "^5.0.0",
    "@angular/language-service": "^5.0.0",
    "@types/jasmine": "~2.5.53",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "^4.0.1",
    "jasmine-core": "~2.6.2",
    "jasmine-spec-reporter": "~4.1.0",
    "karma": "~1.7.0",
    "karma-chrome-launcher": "~2.1.1",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.2.0",
    "tslint": "~5.7.0",
    "typescript": "~2.4.2"
  }

app.component.html:

<button mat-button>My Button</button>

<router-outlet></router-outlet>

material.module.ts:

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

@NgModule({
  imports: [MatButtonModule],
  exports: [MatButtonModule],
})
export class MaterialModule { }

app.module.ts:

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import {MaterialModule} from './material.module';
import { AppComponent } from './app.component';
import {RouterModule} from '@angular/router';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    MaterialModule,
    RouterModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Console Window Error:

回答1:

The error is completely unrelated to the material modules.

Two things need to be done before using the <router-outlet> directive:

Import the RouterModule (or any of the "versions" of it generated by forRoot or forChildren methods) into the module that declares components that use the directive.
The forRoot method of the RouterModule has to be called. Otherwise the services required by the directive wont be initialized.

So basically, change the following:

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    MaterialModule,
    RouterModule.forRoot([])
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

As mentioned by other user, you haven't really configured any routes, so the use of <router-outlet> isn't necessary.

This is basically a dup of No provider for ChildrenOutletContexts (injectionError) (found it by searching the error message in google, 1st result). For a next time do some research before creating a question.

回答2:

Problem is not with Angular-material but with RouterModule. Import it and add it into imports array.

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

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,    
    BrowserAnimationsModule,

    RouterModule,                   //<=======add RouterModule

    MaterialModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

来源：https://stackoverflow.com/questions/47606310/error-no-provider-for-childrenoutletcontexts

标签

angular

angular-material