有问题的angularjs http.get与params

Question

当我在http.get中使用params时，我遇到了一些问题。我无法从http获取数据 这是我的JS

.controller('HomeCtrl', function ($scope, kaka, $ionicPopup,  $http){
 $scope.item ={};
              $scope.code = {};
              $scope.sizes = [ {code: 123456789, name: 'Modul 1'}, {code: 864369038796946, name: 'Modul 4'},
                                {code: 864369038803833, name: 'Modul 5'}, {code: 864369038816645, name: 'Modul 6'},
                                {code: 864369038797142, name: 'Modul 7'}, {code: 864369038796698, name: 'Modul 8'}];
                $scope.update = function(selected) {
                   $scope.item = selected;
                };
 var config = {
                    params: {
                        tN: "find",
                        f12: +$scope.item.code
                    }
                };

                $http.get('http://192.168.100.13:88/OMG1/web.php', config)
               // $http.get('http://192.168.100.13:88/OMG1/web.php?tN=find&f12=123456789')
                  .success(function(data, status, headers,config){
                    console.log('data success');
                    console.log(data); // for browser console
                    $scope.result = data; // for UI
                  })
                  .error(function(data, status, headers,config){
                    console.log('data error');
                  })
                  .then(function(result){
                    things = result.data;
                  });
                  $scope.result = {};
                $scope.findbtn = function () {
                    var lat = parseFloat($scope.result.latitude);
                    var lng = parseFloat($scope.result.longitude);
                    var mylatlng = {lat: lat, lng: lng};
                    var map = new google.maps.Map(document.getElementById('map'), {
                        zoom: 15,
                        center: {lat: -7.3342266, lng: 112.7650341},
                        //center: {lat: data[0].lat, lng: data[0].lng},
                        mapTypeId: 'terrain'
                    });
                    var marker = new google.maps.Marker({
                        position: mylatlng,
                        map: map,
                        title: 'Your Motor'
                    });
                };
})

当我在crome调试器中使用params f12: +$scope.item.code时出现问题我查看$scope.result显示错误Undefined variable : msg但是如果我将params f12更改为{{ 1}}它正常工作。 我不知道如何解决它，p