Angular Reactive formArray中的单选按钮-选择数组中的一项

Question

我有一个名为“地址”的表单数组，这将是一个动态的，一旦用户立即单击“添加地址”按钮，就会添加一个地址表单。每个地址表单都有一个单选按钮 - 用户需要选择任何具有 PRIMARY 地址的地址（即，用户需要选择数组中的一项）。

我参考了以下问题，但它现在完全满足了我的要求 Angular formArray radio buttons 在上述问题中，每个项目都有一组单选按钮（即项目内的选择）

StackBlitz 中提供了工作代码：https://stackblitz.com/edit/angular-reactiveform-radiobutton-in-arrayform

源代码：AppComponent.ts

import { Component } from '@angular/core';
import { FormBuilder, FormGroup, FormArray, Validators } from '@angular/forms';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular';
  public userForm: FormGroup;

  constructor(private _fb: FormBuilder) {
    this.userForm = this._fb.group({
      firstName: [],
      lastName: [],
      address: this._fb.array([this.addAddressGroup()])
    });
  }

  private addAddressGroup(): FormGroup {
    return this._fb.group({
      street: [],
      city: [],
      state: [],
      isPrimary: []
    });
  }

  get addressArray(): FormArray {
    return <FormArray>this.userForm.get('address');
  }

  addAddress(): void {
    this.addressArray.push(this.addAddressGroup());
  }

  removeAddress(index: number): void {
    this.addressArray.removeAt(index);
  }
}

源码：AppComponent.html

<form class="example-form" [formGroup]="userForm">
  <div>
    <mat-card class="example-card">
      <mat-card-header>
        <mat-card-title>Users Creation</mat-card-title>
      </mat-card-header>
      <mat-card-content>
        <div class="primary-container">
          <mat-form-field>
            <input matInput placeholder="First Name" value="" formControlName="firstName">
          </mat-form-field>
          <mat-form-field>
            <input matInput placeholder="Last Name" value="" formControlName="lastName">
          </mat-form-field>
        </div>
        <div formArrayName="address">
          <div class="address-container" *ngFor="let group of addressArray.controls; let i = index;"
            [formGroupName]="i">
            <fieldset>
              <legend>
                <h3>Address: {{i + 1}}</h3>
              </legend>
              <mat-radio-button class="example-radio-button" value="true" checked="true" formControlName="isPrimary">
                Primary
              </mat-radio-button>
              <div>
                <mat-form-field>
                  <input matInput placeholder="Street" value="" formControlName="street">
                </mat-form-field>
                <mat-form-field>
                  <input matInput placeholder="City" value="" formControlName="city">
                </mat-form-field>
                <mat-form-field>
                  <input matInput placeholder="State" value="" formControlName="state">
                </mat-form-field>
              </div>
            </fieldset>
          </div>
        </div>
        <div class="form-row org-desc-parent-margin">
          <button mat-raised-button (click)="addAddress()">Add more address</button>
        </div>
      </mat-card-content>
    </mat-card>
  </div>
</form>
<mat-card class="pre-code">
  <mat-card-header>
    <mat-card-title>Users Information</mat-card-title>
  </mat-card-header>
  <mat-card-content>
    <pre>{{userForm.value | json}}</pre>
  </mat-card-content>
</mat-card>

请帮助我如何从 N 个地址中选择一个地址作为 PRIMARY。只有一个地址属性“isPrimary”应该是true，其他项目都应该是false

Answer 1

在一个新项目中，我仅使用材质组件就实现了这一点，而不涉及事件/循环...... 关键是使用 mat-radio-group 的 name 属性来使无线电组的所有迭代都表现为一个。

<mat-radio-group [formControl]="userForm.controls.primary" name="primary">

我还为“isPrimary”检查使用了不同的方法。我没有在每个地址实例中使用布尔属性，而是在用户模型中使用了一个属性“主地址索引”，因此当您单击单选按钮时，主字段的值将使用当前元素的索引进行更新([value]="i")

<mat-radio-button [value]="i">Primary</mat-radio-button>

这是我的完整表格

<form [formGroup]="userForm" (ngSubmit)="onSubmit()">
    name
    <input formControlName="name" /><br>
    email
    <input formControlName="email" /><br>
    VAT
    <input formControlName="VAT" /><br>

    <button (click)="addNewAddress()">Add new address</button><br>

    <div formArrayName="addresses">
        <div *ngFor="let address of userForm.get('addresses').controls; let i=index">
            <h3>ADDRESS {{i+1}}: </h3>
            primary
            <mat-radio-group [formControl]="userForm.controls.primary" name="primary">
                <mat-radio-button [value]="i">Primary
                </mat-radio-button>
            </mat-radio-group>


            <div [formGroupName]="i">
                street
                <input formControlName="street" /><br>
                city
                <input formControlName="city" /><br>
                country
                <input formControlName="country" /><br>
                zip
                <input formControlName="zip" /><br>

                <button (click)="deleteAddress(i)">
                    Delete <address></address>
                </button>
            </div>
        </div>
    </div>
    <button type="submit" [disabled]="userForm.pristine || !userForm.valid">Save</button>
</form>

这里是ts相关部分：

initForm() {
   this.detailForm = this.fb.group({
        name: ['', Validators.required],
        VAT: ['', Validators.required],
        fiscalCode: ['', Validators.required],
        legalEntity: ['',],
        email: ['', Validators.email],
        primary: [0, Validators.required], //when creating a new customer, set first address as primary
        addresses: this.fb.array([]),
      });
}

addNewAddress(addr: Address): void {
    let control = <FormArray>this.detailForm.controls.addresses;
    control.push(
      this.fb.group({
        street: ['', Validators.required],
        city: ['', Validators.required],
        country: ['', Validators.required],
        zip: [''],
      })
    );
  }

希望这能有所帮助！