使用angular2形成maxlength字段验证

Question

如何验证用户名与最大长度或使用MINLENGTH场angular2 不使用formbuilder.

我尝试了以下方式,但没有工作

<ion-item>
        <ion-icon name="person" item-left class="placeholder-icon"></ion-icon>
        <ion-label floating primary>Username</ion-label>
        <ion-input [(ngModel)]="login.username" ngControl="username" type="text" #username="ngForm" ng-minlength="5" required>
        </ion-input>
      </ion-item>

      <div [hidden]="username.valid || username.pristine">
        <p *ngIf="username.errors && username.errors.required" danger padding-left>
            user name is required
        </p>
        <p *ngIf="username.errors && username.errors.minlength" danger padding-left>
            min length atleast 5
        </p>
      </div>    
<ion-item>

Answer 1

只需添加minlength到您的输入元素.这样,MinLengthValidator指令将自动添加并注册为验证器:

<ion-input [(ngModel)]="login.username"
       ngControl="username" type="text"
       #username="ngForm" minlength="5" required>