css Angular 16 -无法绑定到'formGroup',因为它不是'form'的已知属性

jaql4c8m  于 2023-05-19  发布在  Angular
关注(0)|答案(1)|浏览(164)

我已经有一个正在运行的Angular应用程序,因为有功能扩展,我必须实现应用程序的路由和登录页面。以前没有路由,作为路由的一部分,我添加了以下代码。
app.modules.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { SignUpComponent } from './sign-up/sign-up.component';
import { LoginComponent } from './login/login.component';
import {CommonModule} from "@angular/common";
import {FormsModule , ReactiveFormsModule } from '@angular/forms';

@NgModule({
  declarations: [
    AppComponent,
    HomeComponent,
    SignUpComponent,
    LoginComponent,

  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    CommonModule,
    ReactiveFormsModule,
    FormsModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

sign-up.componnent.ts

import {Component, OnInit} from '@angular/core';
import {FormBuilder, FormControl, FormGroup, FormsModule, ReactiveFormsModule} from '@angular/forms';

@Component({
  selector: 'app-sign-up',
  templateUrl: './sign-up.component.html',
  styleUrls: ['./sign-up.component.css']
})

export class SignUpComponent implements  OnInit{

  public signupFrom : FormGroup|any;
  constructor(private formBuilder: FormBuilder) {}

  items : Array<any> = [
    {name:"username", type:"text", data:"Username"},
    {name:"password", type:"password",data:"Password"},
    {name:"email", type:"text",data:"Email"}

  ]


  ngOnInit(): void {
    this.signupFrom = new FormGroup({

      'Username' : new FormControl(),
      'Passoword' : new FormControl(),
      'Email' : new FormControl()
    })
  }
}

sign-up.component.htm

<div class="row">
  <div class="mx-auto col-10 col-md-8 col-lg-6">
    <!-- Form -->
    <form [formGroup]="signupFrom" class="form-example"  >
      <div *ngFor="let item of items " class="form-group"  >
        <label for="{{item.name}}">{{item.data}}</label>
        <input

          type="{{item.type}}"
          class="form-control {{item.name}}"
          id="{{item.name}}"
          placeholder="{{item.data}}..."
          name="{{item.data}}"
        />
      </div>


      <button type="submit" class="btn btn-primary btn-customized mt-4">
        Sign Up
      </button>
    </form>
    <!-- Form end -->
  </div>
</div>

当我尝试执行ng-serve时,我得到以下错误:无法绑定到“formGroup”,因为它不是“form”的已知属性。

h5qlskok

h5qlskok1#

我看到代码是正确的,除了一些点:
1.组件中never的模块应该导入。
1.将formGroup声明为:public signupFrom! : FormGroup(the!对typeScript说“我知道一开始表单可以是null或undefined”)。
1.通常,当我们在app.module.ts中导入一个新模块时,我们需要“重启”NG服务器
1.您应该在.html中使用绑定和formControlName,否则输入不会与formGroup的formControl“连接”。
1.请参阅 *ngIf以避免初始错误

<!--the *ngIf avoid initial errors-->
<form *ngIf="signupForm" [formGroup]="signupFrom" class="form-example"  >
  <div *ngFor="let item of items " class="form-group"  >
    <label for="{{item.name}}">{{item.data}}</label>
    <!--"better" use binding [ ] instead of interpolation {{ }}-->
    <input

      [type]="item.type"
      [class]="'form-control '+item.name"
      [id]="item.name"
      [placeholder]="item.data+'...'"
      [formControlName]="item.name"
    />
  </div>
  <button type="submit" class="btn btn-primary btn-customized mt-4">
    Sign Up
  </button>
</form>

1.注意:要小心,当你创建formGroup时,你就被写入了

'Passoword' : new FormControl(), //<--should be Password (without the "o")?

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