Angularjs ng类的行为不正常

我有以下几行代码，其中包含ng repeat和ng class：

<div ng-repeat="invitee in invitedCollaborators" class="invite-collabs-emails">
     <input type="text" id="email-{{$index}}" validate-email="email.invalid" ng-class="{'collabs-email-required' : ((invitedCollaborators[{{$index}}].email == null || invitedCollaborators[{{$index}}].email ==''))}" class="collabs-email" placeholder="Enter email here" ng-required="true" ng-model="invitee.email"/>
     <a href ng-click="removeInvitee($index)" class="delete-invite">
       <img src="delete-invite.png">
     </a>
    </div>
<a href class="add-another-collabs-link" ng-click="addAnotherCollaborator()">Add another</a>

在这里，上述问题得到解决，但当输入框失去焦点时，它不会显示红色边框。当它不对焦并且没有用有效id填充（或者根本没有填充）时，它应该有红色边框

我错过了什么条件？请帮忙。谢谢你试试这个

  <div ng-repeat="invitee in invitedCollaborators" class="invite-collabs-emails">
         <input type="text" id="email-{{$index}}" validate-email="email.invalid" ng-class="{'collabs-email-required' : ((invitedCollaborators[$index].email == null || invitedCollaborators[$index].email ==''))}" class="collabs-email" placeholder="Enter email here" ng-required="true" ng-model="invitee.email"/>
         <a href ng-click="removeInvitee($index)" class="delete-invite">
           <img src="delete-invite.png">
         </a>
        </div>
    <a href class="add-another-collabs-link" ng-click="addAnotherCollaborator()">Add another</a>

ng-

part已使其具有角度，您不需要变量使用

{{…}

，因此使用

$index

而不使用brackets@AlekseySolovey，嘿，伙计，谢谢你的快速回复，我删除了$index周围的角度表达式并尝试了一下，效果非常好。。真是个愚蠢的错误1.谢谢你的回复。正如Alexey所建议的那样，我删除了$index周围的表达式，它起了作用

  <div ng-repeat="invitee in invitedCollaborators" class="invite-collabs-emails">
         <input type="text" id="email-{{$index}}" validate-email="email.invalid" ng-class="{'collabs-email-required' : ((invitedCollaborators[$index].email == null || invitedCollaborators[$index].email ==''))}" class="collabs-email" placeholder="Enter email here" ng-required="true" ng-model="invitee.email"/>
         <a href ng-click="removeInvitee($index)" class="delete-invite">
           <img src="delete-invite.png">
         </a>
        </div>
    <a href class="add-another-collabs-link" ng-click="addAnotherCollaborator()">Add another</a>