Don't Fill Data to dropdown list in angularjs!

I write this code, but not work!!

please help me.

Controller:

(function () {

appModule.controller('education.views.students.createOrEditModal', [

'$scope', '$window','$uibModalInstance', 'abp.services.app.student', 'studentId', 'abp.services.app.city', 'uiGridConstants',

function ($scope, $window, $uibModalInstance, studentService, studentId, cityService, uiGridConstants) {

var vm = this;

vm.saving = false;

vm.student = null;

vm.selectedCity = null;

vm.Cities = [];

vm.GetValue = function () {

var CityId = vm.selectedCity.Id;

var CityName = vm.selectedCity.Name;

//console.log(CityId, CityName);

cityService.getCities({

}).then(function (result) {

vm.Cities = result.data;

//console.log(vm.Cities);

});

};

cshtml:

@*selected Value is : {{selectedCity}}*@