javascript - 如何更改输入文本并随后存储它？

Question

这个问题已经有答案了:

Can't bind to 'formGroup' since it isn't a known property of 'form' (48 个回答)

已关闭 3 年前。

我有一个输入字段，用户应该能够在其中更改他的名字。那么可以操作该字段，并且当终止时新字符串应该存储为新用户名吗？我试图用 form 来实现这一点但我收到此错误:Error: Template parse errors: Can't bind to 'formGroup' since it isn't a known property of 'form' 。

这是我的代码

page.html

<form [formGroup]="form" (ngSubmit)="changeName()">
    <ion-list no-border>

        <ion-list-header>
          My Account
        </ion-list-header>

        <ion-item >
          👤 
       <ion-input>{{username}}</ion-input>
        </ion-item>
  ...

      </ion-list>
    </form>

page.ts

import { FormGroup, FormControl, Validators} from '@angular/forms';
...
form: FormGroup;

public usernameInput = '';
...

constructor() {}

...

changeName() {
  this.usernameInput = '';
}

 ngOnInit() {
    this.form = new FormGroup({
     username: new FormControl(null, {
       updateOn: 'submit',
       validators: [Validators.required, Validators.maxLength(20), Validators.minLength(1)]
     })
 });
}

Answer 1

将 ReactiveFormsModule 导入到您的功能模块。