AngularJS：当我使用jQuery的input.val()输入时，ng-change不起作用。

我在一个项目中使用AngularJS和jQuery。当我输入时，ng-change工作正常。但是，当我使用jQuery的input.val(\'blabla\')时，ng-change不起作用。我应该如何在AngularJS中报告这个变化？这是我的代码。使用apply、watch还是其他方法？\n

// HTML
    
    // jQuery代码
    $('.city-input').val('İstanbul');
    // 所有的AngularJS代码
    var app = angular.module('weatherApp', []);
    app.controller('weatherCtrl', ['$scope', 'weatherService', function($scope, weatherService) {
        function fetchWeather(city) {
            weatherService.getWeather(city).then(function(data){
                $scope.items = data;
            });
        }
        $scope.findWeather = function(city) {
            $scope.items = '';
            fetchWeather(city);
            alert(city);
        };
    }]);
    app.factory('weatherService', ['$http', '$q', function ($http, $q){
        function getWeather (city) {
            var deferred = $q.defer();
            var query = 'select * from weather.forecast where woeid in (select woeid from geo.places(1) where text="'+city+'")',
                url   = "http://query.yahooapis.com/v1/public/yql?q=" + query + "&format=json&callback=";
            $http.get(url)
                .success(function(data){
                    deferred.resolve(data.query.results.channel.item.forecast);
                    console.log(data)
                })
                .error(function(err){
                    console.log('Error retrieving markets');
                    deferred.reject(err);
                });
            return deferred.promise;
        }
        return {
            getWeather: getWeather
        };
    }]);