错误 TS2739：类型“AbstractControl”缺少类型“FormControl”中的以下属性：registerOnChange、registerOnDisabledChange

我是 Angular 的新手，正在学习使用的在线课程角10但卡在某一点上。我正在努力实施反应形式。 为此，我添加了一个新组件文本输入。代码为text-input.component.ts如下：

import { Component, Input, Self } from '@angular/core';
import { ControlValueAccessor, NgControl } from '@angular/forms';

@Component({
  selector: 'app-text-input',
  templateUrl: './text-input.component.html',
  styleUrls: ['./text-input.component.css']
})
// We need to implement a control value accessor
export class TextInputComponent implements ControlValueAccessor {
  @Input() label: string;
  @Input() type = 'text';

  constructor(@Self() public ngControl: NgControl) {
    this.ngControl.valueAccessor = this;
  }
  writeValue(obj: any): void {
  }

  registerOnChange(fn: any): void {
  }

  registerOnTouched(fn: any): void {
  }
}

这是代码text-input.component.html

<div class="form-group">
    <input [class.is-invalid]="ngControl.touched && ngControl.invalid" type="{{type}}" 
    class="form-control"
    [formControl]="ngControl.control" placeholder="{{label}}">

    <div *ngIf='ngControl.control.errors?.required' class="invalid-feedback">Please enter a {{label}}</div>
    <div *ngIf='ngControl.control.errors?.minlength' 
    class="invalid-feedback">{{label}} must be at least {{ngControl.control.errors.minlength['requiredLength']}}</div>

    <div *ngIf='ngControl.control.errors?.maxlength' class="invalid-feedback">{{label}} must be at most {{ngControl.control.errors.maxlength['requiredLength']}}</div>

    <div *ngIf='ngControl.control.errors?.isMatching' class="invalid-feedback">
        Password do not match</div>
</div>

但是一旦我添加代码[formControl]我开始收到错误：

 Type 'AbstractControl' is missing the following properties from type 'FormControl': registerOnChange, registerOnDisabledChange, _applyFormState

4     [formControl]="ngControl.control" placeholder="{{label}}">
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  src/app/_forms/text-input/text-input.component.ts:6:16
    6   templateUrl: './text-input.component.html',
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Error occurs in the template of component TextInputComponent.

课程讲师尝试使用该组件在寄存器组件内生成输入控件，代码如下所示register.component.html

<form [formGroup]="registerForm" (ngSubmit)="register()" autocomplete="off">
    <h2 class="text-center text-primary">Sign up</h2>
    <hr>
    <app-text-input [formControl]='registerForm.controls["username"]' [label]='"Username"'></app-text-input>



    <div class="form-group text-center">
        <button class="btn btn-dark mr-2" type="submit">Register</button>
        <button class="btn btn-success mr-2" (click)="cancel()" type="button">Cancel</button>
    </div>
</form>

并且可以看到register.component.ts

import { Component, EventEmitter, OnInit, Output } from '@angular/core';
import { AbstractControl, FormBuilder, FormControl, FormGroup, ValidatorFn, Validators } from '@angular/forms';
import { ToastrService } from 'ngx-toastr';
import { AccountService } from '../_services/account.service';

@Component({
  selector: 'app-register',
  templateUrl: './register.component.html',
  styleUrls: ['./register.component.css']
})
export class RegisterComponent implements OnInit {
  @Output() cancelRegister = new EventEmitter();
  model: any = {};
  registerForm: FormGroup;
  constructor(private accountService: AccountService, private toastr: ToastrService, private fb: FormBuilder) { }

  ngOnInit(): void {
    this.intitializeForm();
  }
  intitializeForm() {
    this.registerForm = this.fb.group({
      username: ['', Validators.required]
      
    })
  } 
  register = () => {
    console.log(this.registerForm.value);
   
  }  
}

请让我知道你还需要什么，作为 Angular 的新手，我无法找到路线原因，但如果你帮助我，那么我将进一步推进我的课程，我将非常感激。

这里有各种建议供您选择AbstractControl to FormControl。您还可以将模板中的引用替换为例如[formControl]="$any(ngControl.control)". The $any()强制转换运算符 https://angular.io/guide/template-expression-operators#any-type-cast-function是我今天能为模板引擎找到的唯一内置铸造操作符。

如果这让您感到困扰，请点赞并订阅这个非常受欢迎且长期存在的问题 https://github.com/angular/angular/issues/13721这实际上可以提供一个不错的解决方案。