Angular 5 lazy loading Error: Cannot find module

Question

我想使用延迟加载，但我不明白为什么它不起作用，它给我错误 "Cannot find module"。
这是我的环境：
- Angular 5.2.1
- .NET 核心 2
- 网络包 3.10.0
- angular-router-loader 0.8.2
- @angular/cli 1.6.5
我在 loadChildren 中尝试了不同的路径，但始终没有成功，我还暂时禁用了所有守卫和 children 路由。我做错什么了？

文件夹

ClientApp
  app
    components
      users
        users-routing.module.ts
        users.module.ts
  app-routing.module.ts
  app.module.shared.ts

app-routing.module.ts

const appRoutes: Routes = [
    {
        path: 'users',
        loadChildren: './components/users/users.module#UsersModule'/* ,
        canLoad: [AuthGuard] */
    },
    {
        path: '',
        redirectTo: '/login',
        pathMatch: 'full'
    },
    {
        path: '**',
        redirectTo: '/login'
    }
];

@NgModule({
    imports: [
        RouterModule.forRoot(
            appRoutes,
            { enableTracing: false }
        )
    ],
    exports: [
        RouterModule
    ],
    providers: [
        CanDeactivateGuard
    ]
})
export class AppRoutingModule { }

users-routing.module.ts

const usersRoutes: Routes = [
    {
        path: '',
        component: UsersComponent/* ,
        //canActivate: [AuthGuard],
        children: [
            {
                path: 'detail',
                canActivateChild: [AuthGuard],
                children: [
                    {
                        path: ':id',
                        component: UserViewComponent
                    },
                    {
                        path: 'edit/:id',
                        component: UserFormComponent,
                        canDeactivate: [CanDeactivateGuard],
                        resolve: {
                            user: UsersResolver
                          }
                    },
                    {
                        path: '',
                        component: UserFormComponent,
                        canDeactivate: [CanDeactivateGuard]
                    }
                ]
            },
            {
                path: '',
                component: UsersListComponent
            }
        ] */
    }
];

@NgModule({
    imports: [
        RouterModule.forChild(
            usersRoutes
        )
    ],
    exports: [
        RouterModule
    ]
})
export class UsersRoutingModule { }

用户。module.ts

@NgModule({
    imports: [
        CommonModule,
        FormsModule,
        UsersRoutingModule,
        RouterModule
    ],
    declarations: [
        UsersComponent,
        UserFormComponent,
        UsersListComponent,
        UserViewComponent
    ],
    providers: [
        UsersResolver,
        RouterModule
    ]
})
export class UsersModule { }

webpack.config.js

const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');
const AngularCompilerPlugin = require('@ngtools/webpack').AngularCompilerPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;

module.exports = (env) => {
    // Configuration in common to both client-side and server-side bundles
    const isDevBuild = !(env && env.prod);
    const sharedConfig = {
        stats: {
            modules: false
        },
        context: __dirname,
        resolve: {
            extensions: ['.js', '.ts']
        },
        output: {
            filename: '[name].js',
            publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
        },
        module: {
            rules: [{
                    test: /\.ts$/,
                    include: /ClientApp/,
                    use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '@ngtools/webpack'
                },
                {
                    test: /\.html$/,
                    use: 'html-loader?minimize=false'
                },
                {
                    test: /\.css$/,
                    use: ['to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize']
                },
                {
                    test: /\.(png|jpg|jpeg|gif|svg)$/,
                    use: 'url-loader?limit=25000'
                }
            ],
            loaders: [
                {
                  test: /\.ts$/,
                  loaders: [
                    'awesome-typescript-loader'
                  ]
                },
                {
                  test: /\.(ts|js)$/,
                  loaders: [
                    'angular-router-loader'
                  ]
                }
              ]
        },
        plugins: [new CheckerPlugin()]
    };

    // Configuration for client-side bundle suitable for running in browsers
    const clientBundleOutputDir = './wwwroot/dist';
    const clientBundleConfig = merge(sharedConfig, {
        entry: {
            'main-client': './ClientApp/boot.browser.ts'
        },
        output: {
            path: path.join(__dirname, clientBundleOutputDir)
        },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./wwwroot/dist/vendor-manifest.json')
            })
        ].concat(isDevBuild ? [
            // Plugins that apply in development builds only
            new webpack.SourceMapDevToolPlugin({
                filename: '[file].map', // Remove this line if you prefer inline source maps
                moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
            })
        ] : [
            // Plugins that apply in production builds only
            new webpack.optimize.UglifyJsPlugin(),
            new AngularCompilerPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.module.browser#AppModule'),
                exclude: ['./**/*.server.ts']
            })
        ])
    });

    // Configuration for server-side (prerendering) bundle suitable for running in Node
    const serverBundleConfig = merge(sharedConfig, {
        resolve: {
            mainFields: ['main']
        },
        entry: {
            'main-server': './ClientApp/boot.server.ts'
        },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./ClientApp/dist/vendor-manifest.json'),
                sourceType: 'commonjs2',
                name: './vendor'
            })
        ].concat(isDevBuild ? [] : [
            // Plugins that apply in production builds only
            new AngularCompilerPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.module.server#AppModule'),
                exclude: ['./**/*.browser.ts']
            })
        ]),
        output: {
            libraryTarget: 'commonjs',
            path: path.join(__dirname, './ClientApp/dist')
        },
        target: 'node',
        devtool: 'inline-source-map'
    });

    return [clientBundleConfig, serverBundleConfig];
};

tsconfig.json

{
  "compilerOptions": {
    "module": "es2015",
    "moduleResolution": "node",
    "target": "es5",
    "sourceMap": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "skipDefaultLibCheck": true,
    "skipLibCheck": true, // Workaround for https://github.com/angular/angular/issues/17863. Remove this if you upgrade to a fixed version of Angular.
    "strict": true,
    "lib": [ "es6", "dom" ],
    "types": [ "webpack-env" ], 
    "typeRoots": [
      "node_modules/@types"
    ]
  },
  "exclude": [ "bin", "node_modules" ],
  "atom": { "rewriteTsconfig": false }
}

错误信息

Unhandled Promise rejection: Cannot find module './ClientApp/app/components/users/users.module'. ; Zone: angular ; Task: Promise.then ; Value: Error: Cannot find module './ClientApp/app/components/users/users.module'. at vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:34015 at ZoneDelegate.invoke (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117428) at Object.onInvoke (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:5604) at ZoneDelegate.invoke (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117427) at Zone.run (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117178) at vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117898 at ZoneDelegate.invokeTask (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117461) at Object.onInvokeTask (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:5595) at ZoneDelegate.invokeTask (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117460) at Zone.runTask (vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:117228) Error: Cannot find module './ClientApp/app/components/users/users.module'. at http://localhost:5000/dist/vendor.js?v=AdjSBPSITyauSY4VQBBoZmJ6NdWqor7MEuHgdi2Dgko:34015:9 ... [truncated]

编辑

link to stackblitz for testing

Answer 1

它的拼写错误文件夹名称是 Users 而不是 users :

改变

'./components/users/users.module#UsersModule'

到

'./components/Users/users.module#UsersModule'

Answer 2

尝试在你的 user.module.ts 中做：

import {UserRoutes } from './User.routing'

@NgModule({
    imports: [
        CommonModule,
        FormsModule,
        UsersRoutingModule.forChild(UserRoutes), //<-- for child
        RouterModule
    ],
    declarations: [
        UsersComponent,
        UserFormComponent,
        UsersListComponent,
        UserViewComponent
    ],
    providers: [
        UsersResolver,
        RouterModule
    ]
})
export class UsersModule { }

Answer 3

我找到了两个解决方案（通过编辑通过 OP）：

引用模块，在它已经用导入语句解析后：

从'./components/users/users.module'导入{UsersModule};

然后这样引用：

{
    path: 'users',
    loadChildren: () => UsersModule,
    canLoad: [AuthGuard]
}

我已将 ng-router-loader 添加到应用程序 (npm install ng-router-loader --save-dev) 并且我这样设置 Webpack：

     rules: [{
             test: /\.ts$/,
             include: /ClientApp/,
             //use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '@ngtools/webpack'
             use: isDevBuild ? [{ loader: 'ng-router-loader' }, 'awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '@ngtools/webpack'
         },
         {
             test: /\.html$/,
             use: 'html-loader?minimize=false'
         },
         {
             test: /\.css$/,
             use: ['to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize']
         },
         {
             test: /\.(png|jpg|jpeg|gif|svg)$/,
             use: 'url-loader?limit=25000'
         }
     ],

然后通过路径引用模块：

    {
        path: 'users',
        loadChildren: './components/users/users.module#UsersModule',
        canLoad: [AuthGuard]
    }

Answer 4

一般是路径错误。更改路径。

例如，这个解决方案对我有用::

loadChildren: '../changelog/changelog.module#ChangelogModule'

./folder 或 ../folder 或 folder

Answer 5

目前接受的答案建议将 loadChildren 的值从字符串交换为函数，从而消除了在进行生产构建时进行 AOT 编译的可能性。

对我有用的是 1）使用绝对路径 2) 在 projects > 'projectname' > architect > build > options > lazyModules 下的 angular.json 中将延迟加载模块作为字符串数组添加。路径应与 loadChildren 下定义的路径相同。

因此，对于您的情况，我认为这应该适用于您的路由模块：

loadChildren: 'app/components/users/users.module#UsersModule'

并在 angular.json 中，在上面指定的位置添加：

lazyModules: ["app/components/users/users.module"]

Answer 6

假设这是处理延迟加载的 AppModule，并且您的系统的功能与它是同一棵树：

routes: Routes = [
    {
        path: 'files-pannel',
        loadChildren: () => import('./module-folder/module-name.module').then(m => m.ModuleName)
    }
];

Answer 7

你可以这样使用：

const rootRoutes: Routes = [
  { path: 'your-path', loadChildren: () => UsersModule }
];

Answer 8

我在加载我的模块时也遇到了同样的问题，我收到了这个错误错误：找不到模块 'app/users/users.module' 然后在弄清楚它是与路径相关的错误之后这个解决方案对我有用希望它能帮助任何人在路由中添加这条路径

{
   path: 'users',
   loadChildren: '../app/users/users.module#UsersModule'
 }

确定模块文件夹的路径，例如 folder 或 ./folder 或 ../folder

编码愉快！！

Angular 5 lazy loading Error: Cannot find module

Angular 5 lazy loading Error: Cannot find module

angular

webpack

lazy-loading

angular-router-loader