如何以角度 2 的形式显示验证消息? [英] how to show validate message in form in angular 2?

问题描述

我正在尝试以 angular 2 的形式显示验证消息?我收到此错误

无法读取未定义的属性hasError"

我添加了这些行

 <div *ngIf="username.hasError('required') && username.touched"类=错误框">用户名是必需的

<div *ngIf="username.hasError('minlength') && username.touched"类=错误框">最小密码长度为 8!</div>

这是我的代码https://plnkr.co/edit/slhySWT0mJXkloGK1kfO?p=preview

解决方案

这应该可以满足您的需求:

<ion-input type="text" ngControl="username" #username="ngForm"></ion-input>

 <div *ngIf="username.errors?.required && username.touched"类=错误框">需要用户名

<div *ngIf="username.errors?.minlength && username.touched"类=错误框">最小密码长度为 8!</div>

Plunker 示例

I am trying to show validate message in form in angular 2 ? I am getting this error

Cannot read property 'hasError' of undefined

I added these lines

 <div *ngIf="username.hasError('required') && username.touched" 
           class="error-box"> username is required</div>    
       <div *ngIf="username.hasError('minlength') && username.touched" 
           class="error-box"> Minimum password length is 8!</div>

here is my code https://plnkr.co/edit/slhySWT0mJXkloGK1kfO?p=preview

解决方案

This should do what you want:

<ion-input type="text" ngControl="username" #username="ngForm"></ion-input>

 <div *ngIf="username.errors?.required && username.touched" 
           class="error-box"> username is required</div>    
       <div *ngIf="username.errors?.minlength && username.touched" 
           class="error-box"> Minimum password length is 8!</div>

Plunker example

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