最可能的原因是在Zone.js之后加载了Promise polyfill(加载zone.js时不需要填充Promise api

问题描述 投票:3回答:1

我得到错误

            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)

我从发生此错误的地方发布了zone.js的一小部分

     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.)');
            }
        };

抛出以上错误。我确实在努力解决这个问题。

收到此错误时

我在我的项目中有一项任务是导出具有样式的Excel工作表。我找到了一个名为exceljs的包装。包括此之后,我开始收到此错误。

来自exceljs.js自述文件的一些相关文档

## ES5 Imports

要使用ES5转换代码,请使用dist / es5路径。

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

注意: ES5构建对许多不再使用的polyfill具有隐式依赖性由exceljs明确添加。您将需要在依赖项中添加“ core-js”和“ regenerator-runtime”,在exceljs导入之前,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');

Browserify

<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。所以我想念的是。请帮助我。

Angular版本的详细信息。

            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 
javascript angular polyfills zone.js
1个回答
0
投票

您能够解决此问题,在我的项目中包含另一个软件包后,我遇到了完全相同的问题。如果是,请说明问题出在什么地方?

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