Error: No value accessor for form control with name: 'xxx'

在Angular的表单开发中，经常会遇到错误 ‘Error: No value accessor for form control with name: 'xxx'’.

一般在自定义表单上加上‘ngDefaultControl’ 即可解决。

例子：

<input
ngDefaultControl
  *ngSwitchCase="'textbox'"
  [formControlName]="question?.key"
  [id]="question?.key"
  [type]="question?.type"
  [value] = "question?.value"
/>