Question

在离子4中，ionic serve已成功完成。在浏览器中打开应用程序时，出现以下错误，并且没有任何加载。

AppComponent_Host.ngfactory.js? [sm]:1 ERROR TypeError: Class constructor EventEmitter cannot be invoked without 'new'
    at new BackButtonEmitter (platform.js:17)
    at new Platform (platform.js:32)
    at _createClass (core.js:10354)
    at _createProviderInstance (core.js:10321)
    at resolveNgModuleDep (core.js:10266)
    at NgModuleRef_.get (core.js:11373)
    at resolveDep (core.js:11865)
    at createClass (core.js:11736)
    at createDirectiveInstance (core.js:11559)
    at createViewNodes (core.js:13100)

我推荐了Babel error: Class constructor Foo cannot be invoked without 'new'，但没有帮助。

Package.json如下所示。

  "name": "T.S.S",
  "version": "0.0.1",
  "author": "Ionic Framework",
  "homepage": "http://ionicframework.com/",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^6.1.9",
    "@angular/common": "~6.1.1",
    "@angular/core": "^6.1.9",
    "@angular/forms": "~6.1.1",
    "@angular/http": "~6.1.1",
    "@angular/platform-browser": "~6.1.1",
    "@angular/platform-browser-dynamic": "^6.1.3",
    "@angular/router": "~6.1.1",
    "@ctrl/ngx-chartjs": "^1.0.3",
    "@ionic-native/core": "5.0.0-beta.14",
    "@ionic-native/date-picker": "^4.15.0",
    "@ionic-native/ionic-webview": "^5.0.0-beta.17",
    "@ionic-native/splash-screen": "5.0.0-beta.14",
    "@ionic-native/status-bar": "5.0.0-beta.14",
    "@ionic/angular": "^4.0.0-beta.0",
    "angular-2-dropdown-multiselect": "^1.8.1",
    "chart.js": "^2.7.2",
    "cordova-android": "7.0.0",
    "cordova-browser": "5.0.4",
    "cordova-plugin-device": "^2.0.2",
    "cordova-plugin-ionic-keyboard": "^2.1.2",
    "cordova-plugin-ionic-webview": "^2.1.0",
    "cordova-plugin-splashscreen": "^5.0.2",
    "cordova-plugin-statusbar": "^2.4.2",
    "cordova-plugin-whitelist": "^1.3.3",
    "core-js": "^2.5.3",
    "install": "^0.12.1",
    "lodash": "^4.17.10",
    "ng2-datepicker": "^3.1.1",
    "ng4-loading-spinner": "^1.2.3",
    "ngx-owl-carousel": "^2.0.7",
    "rxjs": "6.2.2",
    "typescriptnpm": "^1.0.1",
    "web-animations-js": "^2.3.1",
    "zone.js": "^0.8.26"
  },
  "devDependencies": {
    "@angular-devkit/architect": "~0.7.2",
    "@angular-devkit/build-angular": "^0.7.5",
    "@angular-devkit/core": "~0.7.2",
    "@angular-devkit/schematics": "~0.7.2",
    "@angular/cli": "^6.1.5",
    "@angular/compiler": "^6.1.3",
    "@angular/compiler-cli": "^6.1.6",
    "@angular/language-service": "~6.1.1",
    "@ionic/ng-toolkit": "^1.0.0",
    "@ionic/schematics-angular": "^1.0.0",
    "@types/jasmine": "~2.8.6",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "~10.7.1",
    "codelyzer": "~4.4.2",
    "jasmine-core": "~2.99.1",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~3.0.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "~2.0.0",
    "karma-jasmine": "~1.1.1",
    "karma-jasmine-html-reporter": "^0.2.2",
    "primeicons": "^1.0.0-beta.10",
    "primeng": "^6.1.2",
    "protractor": "~5.4.0",
    "ts-node": "~7.0.0",
    "tslint": "~5.11.0",
    "typescript": "^2.9.2"
  },
  "description": "An Ionic project",
  "cordova": {
    "plugins": {
      "cordova-plugin-whitelist": {},
      "cordova-plugin-device": {},
      "cordova-plugin-splashscreen": {},
      "cordova-plugin-ionic-keyboard": {},
      "cordova-plugin-statusbar": {},
      "cordova-plugin-ionic-webview": {}
    },
    "platforms": [
      "android",
      "browser"
    ]
  }
}

也与Ionic产生了问题。 https://github.com/ionic-team/ionic/issues/15939。

关于使应用程序正常运行的任何建议？

Answer 1

最近对@ionic/angular的{{3}}提交有问题。

要使其正常运行，请删除node_modules/@ionic/angular文件夹并安装旧版本。我运行npm i @ionic/angular@4.0.0-beta.0来解决我的问题。

错误TypeError：如果没有在Ionic 4中使用“ new”，则无法调用类构造函数EventEmitter

1 个答案: