Question

我只是做了从Angular 6到Angular 9的迁移，其中最重要的依赖项之一不能在Angular 6上使用。

我遵循ng update中的步骤：

ng update
ng update rxjs
ng update @angular/cli
ng update @angular/core

问题是我现在有很多模板错误，都与相同的问题有关。

No directive found with exportAs 'ngModel'
No directive found with exportAs 'ngForm'

我在网络上没有发现与v9（仅v2）上的这些错误相关的信息。

以下是与错误有关的部分：

有关ngModel的错误

<input type="text" class="form-control style-input-size" name="UserUpdatedUsername" [(ngModel)]="UserUpdated.username" #myKronozUserUpdatedUsername="ngModel" mdbActive required>

有关ngForm的错误

<form #editUserForm="ngForm" (ngSubmit)="editUserForm.valid && saveUpdateUser()" novalidate class="style-form-edit-user">

FormsModule很好地导入了app.module.ts（这是应用程序内的唯一模块）。 app.module.ts：

import { FormsModule } from '@angular/forms';

@NgModule({
  imports: [FormsModule]
})
export class AppModule {
}

package.json：

  "dependencies": {
    "@agm/core": "^1.1.0",
    "@angular/animations": "^9.0.5",
    "@angular/common": "^9.0.5",
    "@angular/core": "^9.0.5",
    "@angular/forms": "^9.0.5",
    "@angular/platform-browser": "^9.0.5",
    "@angular/platform-browser-dynamic": "^9.0.5",
    "@angular/platform-server": "^9.0.5",
    "@angular/router": "^9.0.5",
    "@ngx-translate/core": "^10.0.2",
    "@ngx-translate/http-loader": "^3.0.1",
    "angular-csv-files": "^1.0.0",
    "chart.js": "2.5.x",
    "classlist.js": "1.1.x",
    "core-js": "2.4.x",
    "crypto-js": "^3.1.9-1",
    "easy-pie-chart": "2.1.x",
    "font-awesome": "4.7.x",
    "hammerjs": "2.0.x",
    "jarallax": "^1.10.3",
    "moment-timezone": "^0.5.21",
    "ng-html-util": "1.0.x",
    "ng-recaptcha": "^4.3.0",
    "ng-uikit-pro-standard": "/!\ sensible value /!\",
    "ng2-file-upload": "^1.3.0",
    "ngx-facebook": "^2.4.0",
    "ngx-pagination": "^3.2.1",
    "node-sass": "^4.13.1",
    "rxjs": "^6.5.4",
    "rxjs-compat": "^6.3.3",
    "screenfull": "3.3.x",
    "smoothscroll-polyfill": "0.3.x",
    "tslib": "^1.10.0",
    "web-animations-js": "^2.3.2",
    "zone.js": "~0.10.2"
  },
  "devDependencies": {
    "@angular/cli": "^9.0.5",
    "@angular/compiler-cli": "^9.0.5",
    "@angular/language-service": "^9.0.5",
    "@angular/compiler": "^9.0.5",
    "@types/jasmine": "2.5.38",
    "@types/node": "^12.11.1",
    "codelyzer": "^5.1.2",
    "jasmine-core": "~2.5.2",
    "jasmine-spec-reporter": "~3.2.0",
    "karma": "~1.4.1",
    "karma-chrome-launcher": "~2.0.0",
    "karma-cli": "~1.0.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "karma-coverage-istanbul-reporter": "^0.2.0",
    "protractor": "~5.1.2",
    "ts-node": "~3.2.0",
    "tslint": "~5.7.0",
    "typescript": "~3.7.5",
    "webpack": "^4.3.0",
    "@angular-devkit/build-angular": "~0.900.5"
  }

我为迁移错过了什么吗？谢谢。

Answer 1

由于Angular 9中仅模板变量已被删除，因此您会收到错误消息。这样做是因为它们的类型为any，并且允许进行突变。通常，这是一种反模式。展望未来，您的元素将被强类型化。

在Angular版本<= 8中，以下代码有效。 #TranslateBtn您可以引用translate属性，因为它的类型为any。

<button
  #translateBtn
  (click)="translateBtn.translate = !translateBtn.translate"
>
  Translate
</button>

在Angular 9中，#translateBtn的类型为HTMLButtonElement，不具有translate属性。相反，您可以使用在组件上调用函数的事件来代替该功能。

HTML：

<button (click)="ontTranslate()">
  Translate
</button>

TS：

export class PeopleListComponent {
  translateToWookiee = false;

  onTranslate(): void {
    this.translateToWookiee = !this.translateToWookiee;
  }
}

我的答案来自Angular and Web Technologies的Google开发专家Brian Love的博客article。

Answer 2

建议遵循官方指南：https://update.angular.io/。

建议先更新到版本8，然后再更新到版本9。

遵循此模式，应使用Angular原理图工具自动处理所有不兼容性。

迁移Angular 6-> 9后出现模板错误

2 个答案: