“错误:没有覆盖提供程序！”

Question

在用Angular 2.0.0-rc.7构建的Angular Material 2.0.0-alpha.8-1 +rc.5应用程序中，从rc.5+alpha.7-4 (通过1.0.0-beta.11-webpack.8 NG )升级后会出现以下错误：

main.bundle.js:44545 Error: No provider for Overlay!
    at NoProviderError.Error (native)
    at NoProviderError.BaseError [as constructor] (http://localhost:4200/main.bundle.js:7032:34)
    at NoProviderError.AbstractProviderError [as constructor] (http://localhost:4200/main.bundle.js:44258:16)
    at new NoProviderError (http://localhost:4200/main.bundle.js:44289:16)
    at ReflectiveInjector_._throwOrNull (http://localhost:4200/main.bundle.js:65311:19)
    at ReflectiveInjector_._getByKeyDefault (http://localhost:4200/main.bundle.js:65339:25)
    at ReflectiveInjector_._getByKey (http://localhost:4200/main.bundle.js:65302:25)
    at ReflectiveInjector_.get (http://localhost:4200/main.bundle.js:65111:21)
    at NgModuleInjector.get (http://localhost:4200/main.bundle.js:45173:52)
    at ElementInjector.get (http://localhost:4200/main.bundle.js:65475:48)ErrorHandler.handleError @ main.bundle.js:44545
main.bundle.js:44548ERROR CONTEXT:ErrorHandler.handleError @ main.bundle.js:44548

我的package.json依赖关系是：

  "dependencies": {
    "@angular/common": "2.0.0-rc.7",
    "@angular/compiler": "2.0.0-rc.7",
    "@angular/core": "2.0.0-rc.7",
    "@angular/forms": "2.0.0-rc.7",
    "@angular/http": "2.0.0-rc.7",
    "@angular/platform-browser": "2.0.0-rc.7",
    "@angular/platform-browser-dynamic": "2.0.0-rc.7",
    "@angular/router": "3.0.0-rc.3",
    "core-js": "^2.4.1",
    "rxjs": "5.0.0-beta.12",
    "ts-helpers": "^1.1.1",
    "zone.js": "^0.6.21",
    "@angular2-material/button": "2.0.0-alpha.8-1",
    "@angular2-material/button-toggle": "2.0.0-alpha.8-1",
    "@angular2-material/card": "2.0.0-alpha.8-1",
    "@angular2-material/checkbox": "2.0.0-alpha.8-1",
    "@angular2-material/core": "2.0.0-alpha.8-1",
    "@angular2-material/grid-list": "2.0.0-alpha.8-1",
    "@angular2-material/icon": "2.0.0-alpha.8-1",
    "@angular2-material/input": "2.0.0-alpha.8-1",
    "@angular2-material/list": "2.0.0-alpha.8-1",
    "@angular2-material/menu": "2.0.0-alpha.8-1",
    "@angular2-material/progress-bar": "2.0.0-alpha.8-1",
    "@angular2-material/progress-circle": "2.0.0-alpha.8-1",
    "@angular2-material/radio": "2.0.0-alpha.8-1",
    "@angular2-material/sidenav": "2.0.0-alpha.8-1",
    "@angular2-material/slide-toggle": "2.0.0-alpha.8-1",
    "@angular2-material/slider": "2.0.0-alpha.8-1",
    "@angular2-material/tabs": "2.0.0-alpha.8-1",
    "@angular2-material/toolbar": "2.0.0-alpha.8-1",
    "@angular2-material/tooltip": "2.0.0-alpha.8-1"
  },

和

  "devDependencies": {
    "@types/jasmine": "^2.2.30",
    "angular-cli": "1.0.0-beta.11-webpack.9-1",
    "codelyzer": "~0.0.26",
    "jasmine-core": "2.4.1",
    "jasmine-spec-reporter": "2.5.0",
    "karma": "1.2.0",
    "karma-chrome-launcher": "^2.0.0",
    "karma-cli": "^1.0.1",
    "karma-jasmine": "^1.0.2",
    "karma-remap-istanbul": "^0.2.1",
    "protractor": "4.0.5",
    "ts-node": "1.2.1",
    "tslint": "3.13.0",
    "typescript": "2.0.2"
  }

我的main.ts是：

import './polyfills.ts';

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { environment } from './environments/environment';
import { AppModule } from './app/';

if (environment.production) {
  enableProdMode();
}

platformBrowserDynamic().bootstrapModule(AppModule);

这是我在app.module.ts中的app.module.ts定义

@NgModule({
  declarations: [
    AppComponent,
    // other application-specific components...
    PageNotFoundComponent,
  ],
  imports: [
    BrowserModule,
    CommonModule,
    ReactiveFormsModule,
    MdButtonModule,
    // other MD modules...
    MdTooltipModule,
    OverlayModule,
    PortalModule,
    RtlModule,
    routing        // application routing
  ],
  providers : [
    Title,
    MdIconRegistry,
    // set of application-specific providers...
  ],
  entryComponents: [AppComponent],
  bootstrap: [AppComponent]
})
export class AppModule {

}

知道这是怎么回事吗？

Answer 1

通过将此添加到app.module.js中，我设法消除了此错误：

import {OVERLAY_PROVIDERS} from "@angular/material";

@NgModule({
  imports: [...
  ],
  declarations: [...],
  providers: [OVERLAY_PROVIDERS],
  bootstrap: [...]
})

编辑(2018年5月)：

现在不推荐OVERLAY_PROVIDERS了。使用OverlayModule代替

import { OverlayModule } from '@angular/cdk/overlay';

@NgModule({
  imports: [
      OverlayModule
  ],
  declarations: [...],
  providers: [...],
  bootstrap: [...]
})

Answer 2

您应该执行MaterialModule.forRoot() (参见UPDATE2)来修复这个问题。

FYI，这是基本的maerial2设置：

import { MaterialModule, MdIconRegistry, } from '@angular/material';

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

请参阅更多详细信息，这里是http://iterity.io/2016/10/01/angular/getting-started-with-angular-material-2/

UPDATE1：官方的material2文档已经更新，所以您可能也会看到它，https://material.angular.io/guide/getting-started。

UPDATE2：在最新的material2 ( 2.0.0-beta.2及以上)中，不再需要使用MaterialModule.forRoot()了，只需要使用MaterialModule。

模块forRoot的使用已被取消，并将在下一个版本中删除。相反，只需直接导入MaterialModule：

@NgModule({
    imports: [
        ...
        MaterialModule,
        ...
    ]
...
});

UPFATE3:从2.0.0-beta.8角度材料开始的取决于@angular/cdk，所以您也需要安装npm。

Answer 3

对于@angular/material版本6及更高版本:在根模块中导入OverlayModule (例如，在app.module.ts中)。导入惰性加载模块不起作用！详细信息：https://github.com/angular/material2/issues/10820#issuecomment-386733368