我的 ionic 项目中有一个控制器，用于检查已登录的用户并显示有关该用户的数据。

但是，我尝试显示链接到数据库中当前用户的数据。我试过该代码，但它没有显示它：

.controller('AccountCtrl', function($scope, $state, $cordovaOauth) {
    $scope.$on('$ionicView.enter', function() {
    //Get logged in user credentials.
    var user = firebase.auth().currentUser;
    var name, email, photoUrl, provider, description;

    console.log("User: " + JSON.stringify(user));
    if (user != null) {
        name = user.displayName;
        email = user.email;
        photoUrl = user.photoURL;
        provider = user.provider;
        uid = user.uid;
    }

    //Set Profile Image.
    $scope.profileImage = photoUrl;
    //Set Profile Name.
    $scope.profileName = name;
    //Set Profile email.
    $scope.profileEmail = email;
    //Set provider.
    $scope.provider = provider;

        var userId = firebase.auth().currentUser;
        var accountRef = firebase.database().ref('accounts/' + userId);
        accountRef.on('value', function(account) {
        $scope.description = account.val().displayDescription;
        $scope.$apply();
    });
     }) ;
    });

但是当我尝试 {{description} 时它没有显示任何内容。

事实上，我尝试让帐户的行在我的数据库中找到链接到当前用户的“displayDescription”，例如用户 -KOkwpzslw9NyUrTtvA7

{
  "accounts" : {
    "-KOjv0LDdoWrc3uApvPi" : {
      "dateCreated" : "Tue Aug 09 2016 11:29:18 GMT-0400 (EDT)",
      "email" : "[email protected]",
      "provider" : "Facebook",
      "userId" : "FMXlUQZth5aehQLT2TKZZJZdJBh2"
    },
    "-KOkwpzslw9NyUrTtvA7" : {
      "dateCreated" : "Tue Aug 09 2016 16:16:52 GMT-0400 (EDT)",
      "displayDescription" : "no description",
      "email" : "[email protected]",
      "provider" : "Facebook",
      "userId" : "F9Z7YhSlmAQqOH5FVjBSV2CkYZG3"
    }
  }
}