javascript - 如何避免 angularjs 选择中的空自动选项？

Question

<form ng-show="editingUser" class="form-inline editingUser" role="form" name="gebruikerdetailform" novalidate>
<input type="text" class="form-control" ng-model="userDetail.name" placeholder="Naam" ng-required="true"/>
<input type="text" class="form-control" ng-model="userDetail.surname" placeholder="Surname"/>
<select class="form-control" ng-model="userDetail.role">
    <option ng-selected="userDetail.role === 'user' || userDetail.role === ''" >user</option>
    <option ng-selected="userDetail.role === 'admin'">admin</option>
</select>
</form>

在此代码中，自动空选项 <option value="? string: ?"></option>由 angularjs 创建。我知道当 ng-model 引用的值在 ng-options 中不存在时会发生这种情况。但事实并非如此，我不明白如何避免这种行为，以及它从何而来。有什么想法吗？

Answer 1

如果问题涉及ng-model 的初始化，您可以使用指令ng-init，如下所示:

<form ng-show="editingUser" class="form-inline editingUser" role="form" name="gebruikerdetailform" novalidate>
  <input type="text" class="form-control" ng-model="userDetail.name" placeholder="Naam" ng-required="true"/>
  <input type="text" class="form-control" ng-model="userDetail.surname" placeholder="Surname"/>
  <select class="form-control" ng-model="userDetail.role" ng-init="user">
    <option ng-selected="userDetail.role === 'user' || userDetail.role === ''" >user</option>
    <option ng-selected="userDetail.role === 'admin'">admin</option>
  </select>
</form>

查看select定义中ng-init指令的用法。

更多信息:https://docs.angularjs.org/api/ng/directive/ngInit

干杯