反应式表单选择标签验证

Question

我正在对select标记进行响应式表单验证，但它的验证不起作用。这是一个基本的反应式表单验证，我已经对其他字段进行了验证，它们正在工作，但对select标记(State输入字段(的一个验证不起作用。

html文件

<div class="container">
<form [formGroup]="info" (ngSubmit)="onSubmit">
<h1>Info</h1>
<div>
<label>First Name</label>
<input
type="text"
formControlName="firstName"
class="form-control"
[ngClass]="{ 'is-invalid': f.firstName.touched && f.firstName.errors }"
/>
<div
*ngIf="f.firstName.touched && f.firstName.errors"
class="alert alert-danger"
>
<div *ngIf="f.firstName.errors.required">First Name is required</div>
<div *ngIf="f.firstName.errors.minlength">Minimum 3 characters</div>
<div *ngIf="f.firstName.errors.maxlength">Maximum 10 characters</div>
<div *ngIf="f.firstName.errors.pattern">Only alphabets</div>
</div>
</div>
<div>
<label>Last Name</label>
<input
type="text"
formControlName="lastName"
class="form-control"
[ngClass]="{'is-invalid':f.lastName.touched && f.lastName.errors}"
/>
<div *ngIf="f.lastName.touched && f.lastName.errors">
<div *ngIf="f.lastName.errors.required">Last name required</div>
<div *ngIf="f.lastName.errors.minlength">Minimum 3 characters</div>
<div *ngIf="f.lastName.errors.maxlength">Minimum 10 characters</div>
</div>
</div>
<div>
<label for="">Gender</label>
<input
type="radio"
formControlName="gender"
class="form-control"
value="male"
/><span>male</span>
<input
type="radio"
formControlName="gender"
class="form-control"
value="female"
/><span>female</span>
<input
type="radio"
formControlName="gender"
class="form-control"
value="other"
/><span>other</span>
<div>
<div *ngIf="f.gender.touched && f.gender.errors">
<div>Gender required</div>
</div>
</div>
</div>
<div>
<label for="state">State</label>
<select id="state" formControlName="state" class="form-control" 
[ngClass]="{'is-invalid':f.state.touched && f.state.errors}">
<option value=""></option>
<option value="Delhi">Delhi</option>
<option value="UP">UP</option>
<option value="Karnataka">Karnataka</option>
<option value="Bihar">Bihar</option>
<div>
<div *ngIf="f.state.errors.touched && f.state.errors">
<div *ngIf="f.state.errors.required">state required</div>
</div></div>
</select>
</div>
<div>
<label for="qualification">qualification</label>
<input
type="checkbox"
formControlName="qualification"
class="form-control"
value="Graduate"
/><span>Graduate</span>
<input
type="checkbox"
formControlName="qualification"
class="form-control"
value="Post Graduate"
/><label>Post Graduate</label>
<div>
<div *ngIf="f.qualification.touched && f.qualification.errors">
<div>qualification required</div>
</div>
</div>
</div>
<div>
<button type="submit" (click)="onSubmit" [disabled]="info.invalid">
submit
</button>
</div>
</form>
</div>

ts文件

import { Component,OnInit } from "@angular/core";
import { FormGroup,FormBuilder, Validators } from "@angular/forms";
@Component({
selector: "app-root",
templateUrl: "./app.component.html",
styleUrls: ["./app.component.css"]
})
export class AppComponent implements OnInit{
title = "CodeSandbox";
info: FormGroup;
submitted:boolean;
regex:any="^[A-Za-z]*";

constructor(private fb:FormBuilder){
}
ngOnInit(){
this.valueInfo();
}
valueInfo(){
this.info=this.fb.group({
firstName:['',[Validators.required,
Validators.minLength(3),
Validators.maxLength(10),
Validators.pattern(this.regex)]],
lastName:['',[Validators.required,
Validators.minLength(3),
Validators.maxLength(10),
Validators.pattern(this.regex)]],
gender:['',Validators.required],
state:['',Validators.required],
qualification:['',Validators.required]
})
}
get f(){
return this.info.controls;
}
}

Answer 1

您已经使用了f.state.errors.touched，它必须只是f.state.touched

<div *ngIf="f.state.touched && f.state.errors">
<div *ngIf="f.state.errors.required">state required</div>
</div></div>

编辑：

我还注意到，您已经将div放在了selectHTMLelement之外，并在select Tag中显示了错误消息，如下所示。

<div>
<label for="state">State</label>
<select id="state" formControlName="state" class="form-control" 
[ngClass]="{'is-invalid':f.state.touched && f.state.errors}">
<option value=""></option>
<option value="Delhi">Delhi</option>
<option value="UP">UP</option>
<option value="Karnataka">Karnataka</option>
<option value="Bihar">Bihar</option>
</select>
<div>
<div *ngIf="f.state.touched && f.state.errors">
<div *ngIf="f.state.errors.required">state required</div>
</div></div>
</div>

我已经创建了一个stackblitz.com和所有的变化。