当我更新“@angular-devkit/build-angular”时，样式加载器停止工作

Question

我正在使用 angular8 并遇到问题，

为了动态加载我的样式，我使用了下面的代码，它工作正常，但是当我将包 "@angular-deficit/build-angular": "^0. 800.0" 更新为 "@angular-deficit/build-angular": "^0. 803.21" 时，它停止工作。该应用程序运行良好，终端和浏览器控制台中没有错误，但应用程序未实现样式。

declare function require(name: string): any;
 ngOnInit() {
    require('style-loader!./file-path');
}

package.json

{
"name": "latest-frontend-theme",
"version": "0.0.0",
"scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "bundle-report": "webpack-bundle-analyzer dist/stats.json"
},
"private": true,
"dependencies": {
    "@agm/core": "^1.1.0",
    "@angular/animations": "^8.2.14",
    "@angular/cdk": "^8.2.3",
    "@angular/common": "~8.2.14",
    "@angular/compiler": "~8.2.14",
    "@angular/core": "~8.2.14",
    "@angular/forms": "~8.2.14",
    "@angular/material": "^8.2.3",
    "@angular/platform-browser": "~8.2.14",
    "@angular/platform-browser-dynamic": "~8.2.14",
    "@angular/router": "~8.2.14",
    "@ngx-loading-bar/core": "^4.2.0",
    "@ngx-loading-bar/router": "^4.2.0",
    "angular2-text-mask": "^9.0.0",
    "crypto-js": "^3.1.9-1",
    "file-saver": "^2.0.2",
    "moment": "^2.24.0",
    "mydatepicker": "^2.6.8",
    "ng2-ckeditor": "^1.2.6",
    "ng2-file-upload": "^1.3.0",
    "ng6-toastr": "^6.0.0",
    "ngx-google-places-autocomplete": "^2.0.4",
    "ngx-slick": "^0.2.1",
    "rxjs": "~6.5.3",
    "rxjs-compat": "^6.5.3",
    "tslib": "^1.9.0",
    "zone.js": "~0.10.2"
},
"devDependencies": {
    "@angular-devkit/build-angular": "~0.803.21",
    "@angular/cli": "~8.3.21",
    "@angular/compiler-cli": "~8.2.14",
    "@angular/language-service": "~8.2.14",
    "@types/jasmine": "~3.5.0",
    "@types/jasminewd2": "~2.0.8",
    "@types/node": "~12.12.21",
    "codelyzer": "^5.2.1",
    "jasmine-core": "~3.5.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~4.4.1",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~2.1.1",
    "karma-jasmine": "~2.0.1",
    "karma-jasmine-html-reporter": "^1.4.0",
    "protractor": "~5.4.0",
    "ts-node": "~8.5.4",
    "tslint": "~5.20.1",
    "typescript": "~3.4.3",
    "webpack-bundle-analyzer": "^3.6.0"
}

}

任何形式的帮助都是可观的。

Answer 1

我今天遇到了同样的问题，但仍然无法使用 style-loader 找到解决方案，因此我想出了一个替代解决方案，我将分享，因为这仍然没有答案。

我以前是这样使用style-loader的：

// in the AppComponent
private initTheme(settings: Settings) {

  if (settings.style) {
    // set specific theme 
    require(`style-loader!./../../src/${settings.style.id}-theme.scss`);
  }
  else {
    require(`style-loader!./../../src/default-theme.scss`);
  }
}

我的解决方案是更新此函数以手动应用样式表（作为已处理的 CSS 文件），如下所示：

// in the AppComponent
private initTheme(settings: Settings) {

  const applyStyleSheet = (styleName: string) => {
    const head = document.getElementsByTagName('head')[0];
    const style = document.createElement('link');
    style.rel = 'stylesheet';
    style.href = `${styleName}.css`;
    head.appendChild(style);
  };

    if (settings.style) {
      // set specific theme
      applyStyleSheet(`${settings.style.id}-theme`);
    }
    else {
      applyStyleSheet(`default-theme`);
    }
  }

为了处理 SCSS 文件，我更改了我的 angular.json 文件，将 extractCss 添加到选项中：

"options": {
  "extractCss": true
  ...
}

...并指定styles数组中的每个SCSS文件要处理，但不注入：

"styles": [
  {
    "input": "src/default-theme.scss",
    "bundleName": "default-theme",
    "inject": false
  },
  {
    "input": "src/basic-theme.scss",
    "bundleName": "basic-theme",
    "inject": false
  }
  ...
]