javascript - 为什么我的变量在 Controller 中未定义，但它在带有数据绑定(bind)的 HTML 页面中正确显示

Question

为什么我从 {{myItem}} 获取数据绑定(bind)的值，但在我的 Controller 中，当我尝试分配我获取或输出到控制台的新变量时，我得到 undefined .

这是我的 Controller :

var controllers = angular.module("myItem.controllers", []);
controllers.controller('myItemController', function ($scope, MyItemService) {
    $scope.version_model = null;
    $scope.itemGroup_model = null;
    $scope.item_model = null;

    $scope.myItem = null;
    $scope.versions = null;
    $scope.itemGroups = null;
    $scope.hierarchies = null;

    $scope.init = function () {

        $scope.myItem = MyItemService.getMyItem();
        console.log("myItem => id= " + $scope.myItem.versionID + " requestTypeID: " + $scope.myItem.requestTypeID);
        $scope.versions = MyItemService.getVersions();
        $scope.version_model = $scope.myItem.versionID;
        console.log("version_model :" + $scope.version_model + "scope.myItem.versionID : " + $scope.myItem.versionID);

        $scope.itemGroups = MyItemService.getItemGroups();
        $scope.itemGroup_model = $scope.myItem.itemGroup;
        console.log("itemGroup_model :" + $scope.itemGroup_model + " scope.myItem.itemGroup : " + $scope.myItem.itemGroup);

        $scope.hierarchies = MyItemService.getItemList($scope.itemGroup_model);
        $scope.item_model = $scope.myItem.itemName;
        console.log("item_model :" + $scope.item_model + " scope.myItem.itemName : " + $scope.myItem.itemName);
    }

    $scope.getItems = function (group) {
        $scope.hierarchies = MyItemService.getHierarchyList(group);
    }

每当我尝试从 $scope.myitem 中分配任何内容时，我都会遇到未定义的情况。我尝试在 init 内部、init 外部进行设置。除了 _model 值未定义的地方，我的页面上的所有内容都有效，一旦我与某些内容交互并且它得到更新，所有内容都可以正常工作，只是不能初始化时

更新

这就是我的服务的样子

angular.module('servicefactories', [])
    .factory('MyItemService', function ($http, $q) {
    obj.getMyItem= function () {
        var mypromise = $q.defer();
        $http.get('getforEdit')
            .success(function (data, status, headers, config) {
            mypromise.resolve(data);
        });

        return mypromise.promise;
    }

    return obj;

});

Answer 1

我怀疑这是异步调用的问题。您可以使用 Promise 上的 then 方法来访问数据并在数据来自服务器后进行分配。类似的东西

MyItemService.getMyItem().then(function(data) {
         $scope.myItem=data;
         console.log("myItem => id= " + $scope.myItem.versionID + " requestTypeID: " + $scope.myItem.requestTypeID);
        $scope.versions = MyItemService.getVersions();
        $scope.version_model = $scope.myItem.versionID;
        console.log("version_model :" + $scope.version_model + "scope.myItem.versionID : " + $scope.myItem.versionID);
});