问题
I have the following input html element that I want to change the placeholder of depending on what is being held in my user model.
<input type="text" class="form-control" id="Username" name="Username" data-ng-model="user.Username" required="" ng-placeholder="{{user.AdAccount ? 'Username' : 'Ad Login'}}">
I even tried this method that is said to have worked in previous versions of angular, but no success.
ng-placeholder="user.AdAccount == true && 'Username' || 'AD Login'"
At the moment my placeholder just appears completely blank. I also know that AdAccount is holding true/false correctly because it is being used elsewhere on the form with ng-show.
回答1:
I don't think there's any ngPlaceholder directive. Try changing your code to:
<input type="text" class="form-control" id="Username" name="Username" data-ng-model="user.Username" required="" placeholder="{{user.AdAccount ? 'Username' : 'Ad Login'}}" />
That is, change ng-placeholderinto just placeholder, and everything should work fine.
(Note also the self-closing slash if you need to conform to valid XHTML.)
回答2:
You can try this:
<input type="text" class="form-control" id="Username" name="Username" data-ng-model="user.Username" required="" ng-attr-placeholder="{{user.AdAccount ? 'Username' : 'Ad Login'}}">
ng-attr- will work with any HTML attribute.
回答3:
In HTML:
<input type="text" placeholder="{{doctorname ? doctorname : 'Dr. your name'}}"
class="editable-class" ng-model="doctor.name" readonly/>
In controller:
$scope.doctorname = $scope.doctorinfo.name;
来源：https://stackoverflow.com/questions/30573999/angularjs-ng-placeholder-not-working