未捕获的错误：模板分析错误：无法绑定到'ng模型'，因为它不是'input'的已知属性

Question

我使用的是Angular 4.2.4，控制台中出现了一个错误：

Uncaught Error: Template parse errors: Can't bind to 'ngModel' since it isn't a known property of 'input'.

而我在app.module.ts文件中包含FormsModule就像as一样

import { FormsModule,ReactiveFormsModule }   from '@angular/forms';
@NgModule({
  declarations: [
    AppComponent,
    ...APP_LAYOUTS,
    ...APP_COMPONENTS,
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    AppRoutingModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})

<form id="user-add-form">
    <div class="text-center m-t-10"><span class="login-img"><i class="ti-check-box"></i></span></div>
    <h3 class="login-title">Add New User</h3>
    <div class="row">
      <div class="col-6">
        <div class="form-group">
          <input class="form-control" type="text" name="first_name" [(ngModel)]="first_name" placeholder="First Name">
        </div>
      </div>
      <div class="col-6">
        <div class="form-group">
          <input class="form-control" type="text" name="last_name" [(ngModel)]="last_name" placeholder="Last Name">
        </div>
      </div>
    </div>
    <div class="form-group">
      <input class="form-control" type="email" name="email" [(ngModel)]="email" placeholder="Email" autocomplete="off">
    </div>
    <div class="form-group">
      <input class="form-control" id="password" type="password" name="password" [(ngModel)]="password" placeholder="Password">
    </div>
    <div class="form-group">
      <input class="form-control" type="password" name="password_confirmation" [(ngModel)]="password_confirmation" placeholder="Confirm Password">
    </div>
    <div class="form-group">
      <button class="btn btn-info btn-block" type="submit">Submit</button>
    </div>
  </form>

import { FormBuilder,Validator } from '@angular/forms';
export class UserAddComponent implements OnInit, OnDestroy, AfterViewInit {
    first_name: string;
    last_name: string;
    email: string;
    password: string;
    password_confirmation: string;

无法绑定到“ng模型”，因为它不是“input”的已知属性

请帮忙解决

Answer 1

从维基，

此错误通常意味着您尚未声明指令“x”或尚未导入“x”所属的NgModule。

如果“x”确实不是属性，或者“x”是私有组件属性（即缺少@input或@output修饰符），则还会出现此错误。

希望能有所帮助！！