为AngularJS中的无效输入字段实现Error-Class

Firstly my HTML Code:

首先是我的HTML代码:

<form name="Form" novalidate>
   <div class="form-group has-error has-feedback">
      <input class="form-control" type="text" name="Name" ng-model="item.name" required="" aria-describedby="" />
      <span class="glyphicon glyphicon-remove form-control-feedback" aria-hidden="true"></span>
      <span class="sr-only">(error)</span>
      <br />
      <div class="has-error has-feedback" ng-show="Form.$submitted || Form.Name.$touched">
         <span ng-show="Form.Name.$error.required">Name is invalid.</span>
      </div>
   </div>
<form na