最可能的原因是在 Zone.js 之后已经加载了一个 Promise polyfill（加载 zone.js 时不需要Polyfilling Promise api

Question

我收到错误

            Error: Zone.js has detected that ZoneAwarePromise `(window|global).Promise` has been overwritten.
      Most likely cause is that a Promise polyfill has been loaded after Zone.js (Polyfilling Promise api is not necessary when zone.js is loaded. If you must load one, do so before loading zone.js.)
          at Function.push../node_modules/zone.js/dist/zone.js.Zone.assertZonePatched (zone.js:58)
          at new NgZone (core.js:24212)
          at getNgZone (core.js:24925)
          at PlatformRef.push../node_modules/@angular/core/fesm5/core.js.PlatformRef.bootstrapModuleFactory (core.js:24823)
          at core.js:24867
          at exceljs.min.js:3
          at MutationObserver.n (exceljs.min.js:3)
          at ZoneDelegate.push../node_modules/zone.js/dist/zone.js.ZoneDelegate.invoke (zone.js:391)
          at Zone.push../node_modules/zone.js/dist/zone.js.Zone.runGuarded (zone.js:161)
          at MutationObserver.<anonymous> (zone.js:144)

我发布了 zone.js 的一小部分，从那里我得到了这个错误

     function Zone(parent, zoneSpec) {
            this._parent = parent;
            this._name = zoneSpec ? zoneSpec.name || 'unnamed' : '<root>';
            this._properties = zoneSpec && zoneSpec.properties || {};
            this._zoneDelegate =
                new ZoneDelegate(this, this._parent && this._parent._zoneDelegate, zoneSpec);
        }
        Zone.assertZonePatched = function () {
            if (global['Promise'] !== patches['ZoneAwarePromise']) {
                throw new Error('Zone.js has detected that ZoneAwarePromise `(window|global).Promise` ' +
                    'has been overwritten.\n' +
                    'Most likely cause is that a Promise polyfill has been loaded ' +
                    'after Zone.js (Polyfilling Promise api is not necessary when zone.js is loaded. ' +
                    'If you must load one, do so before loading zone.js.)');
            }
        };

上面的错误被抛出。我确实在努力解决这个问题。

当我收到此错误时

我的项目中有一项任务是导出带有样式的 Excel 表格。我找到了一个名为exceljs 的包。包含此内容后，我开始收到此错误。

exceljs.js自述文件中的一些相关文档

## ES5 Imports

要使用 ES5 转译代码，请使用 dist/es5 路径。

const ExcelJS = require('exceljs/dist/es5');

注意： ES5 构建对许多不再是 由 exceljs 显式添加。 您需要将“core-js”和“regenerator-runtime”添加到您的依赖项和 在导入 exceljs 之前，在您的代码中包含以下要求：

// polyfills required by exceljs
require('core-js/modules/es.promise');
require('core-js/modules/es.object.assign');
require('core-js/modules/es.object.keys');
require('regenerator-runtime/runtime');

// ...

const ExcelJS = require('exceljs/dist/es5');

浏览

<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-polyfill/6.26.0/polyfill.js"></script>
<script src="exceljs.js"></script>

我正在使用 es6。所以我错过了什么。请帮帮我。

Angular 版本详情。

            Angular CLI: 7.3.9
        Node: 10.0.0
        OS: linux x64
        Angular: 8.0.0
        ... core

        Package                             Version
        -------------------------------------------------------------
        @angular-devkit/architect           0.13.9
        @angular-devkit/build-angular       0.13.9
        @angular-devkit/build-optimizer     0.13.9
        @angular-devkit/build-webpack       0.13.9
        @angular-devkit/core                7.3.9
        @angular-devkit/schematics          7.3.9
        @angular/animations                 7.2.15
        @angular/cdk                        8.1.4
        @angular/cli                        7.3.9
        @angular/common                     7.2.15
        @angular/compiler                   7.2.15
        @angular/compiler-cli               7.2.15
        @angular/forms                      7.2.15
        @angular/http                       7.2.15
        @angular/language-service           7.2.15
        @angular/material                   8.1.4
        @angular/platform-browser           7.2.15
        @angular/platform-browser-dynamic   7.2.15
        @angular/router                     7.2.15
        @ngtools/webpack                    7.3.9
        @schematics/angular                 7.3.9
        @schematics/update                  0.13.9
        rxjs                                6.3.3
        typescript                          3.2.4
        webpack 

Answer 1

到您提出问题时，您现在可能已经想通了...从您的 polyfills.ts 中注释掉这一行

// import 'zone.js/dist/zone'; // Included with Angular CLI.