Angular 6 ng build --prod 错误“错误错误：ngIfElse 必须是 TemplateRef，但收到‘true’。”

ERROR 错误：ngIfElse 必须是 TemplateRef，但收到“true”

HTML 文件

<select class="form-control">
  <option selected value="0">Select Manufacturer</option>
  <option *ngFor="let brand of allMakes">
     {{ brand.brand }}
  </option>
</select>

ts file

this.allMakes = [{
  id: '1',
  brand: 'Mazda'
},
{
  id: '2',
  brand: 'Audi',
}];

这一切都是在我从 Angular 5 升级到 Angular 6 后开始的

控制台日志错误

ERROR Error: ngIfElse must be a TemplateRef, but received 'true'.
  at Vt (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at t.set [as ngIfElse] (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at Sa (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at main.6e360f04b7d39ee1dc33.bundle.js:1
  at main.6e360f04b7d39ee1dc33.bundle.js:1
  at es (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at Os (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at Object.updateDirectives 
  (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at Object.updateDirectives (main.6e360f04b7d39ee1dc33.bundle.js:1)
  at ts (main.6e360f04b7d39ee1dc33.bundle.js:1)

For ngIf与 else 块你需要使用<ng-template>作为 else 中的块.html file.

这是示例代码：

<div *ngIf="condition; else elseBlock">Content to render when condition is true.</div> <ng-template #elseBlock>Content to render when condition is false.</ng-template>