Question

GetAllCountries从控制器操作（MVC）检索国家/地区列表。我无法将国家/地区分配给选择元素（如标记中所示）。另一方面，如果我将值指定为model.countries = ["India","USA"];则可行。如何分配返回值？

var initialData = @Html.Raw(new JavaScriptSerializer().Serialize(Model));


    function StudentViewModel() {
        var self = this;
        self.students = ko.observableArray([]);
        self.countries =[];
        self.editingItem = ko.observable();
        self.isItemEditing = function(itemToTest) {
            return itemToTest == self.editingItem();
        };
    };
    $(document).ready(function () {
        var url = '/GridDemo/GetAllCountries';
        $.ajax({ url: url, success: dataRetrieved, type: 'POST', dataType: 'json' });
        var model = new StudentViewModel();
        //model.countries = ["India","USA"];
        function dataRetrieved(data) {
            var strCountry = [];
            for (var i = 0; i<data.length; i++) {
                strCountry.push(data[i]);
            }
            //alert(strCountry);
           model.countries = strCountry;

        }
       // alert(initialData.country);
        //model.countries = initialData.Countries;
        model.students(initialData);
        ko.applyBindings(model);   

    });

HTML：

 <select class="form-control" data-bind="options: $root.countries, value: 
  Country, visible: $root.isItemEditing($data)"></select>
 <label data-bind="text: Country, visible: !$root.isItemEditing($data)" />

当我弹出json结果时，我得到的确是：印度，美国，尼泊尔。

控制器中的动作：

 public JsonResult GetAllCountries()
        {
            var countries = new[] { "India", "America", "Nepal" };
            return Json(countries, JsonRequestBehavior.AllowGet);
        }

Answer 1

您需要将countries设为ko.observableArray

function StudentViewModel() {
        var self = this;
        self.students = ko.observableArray();
        self.countries = ko.observableArray();
        self.editingItem = ko.observable();
        self.isItemEditing = function(itemToTest) {
            return itemToTest == self.editingItem();
        };
    };

在您的dataRetrieved中，您需要将strCountry分配给model.countries：

function dataRetrieved(data) {
    var strCountry = [];
    for (var i = 0; i<data.length; i++) {
        strCountry.push(data[i]);
    }
    model.countries(strCountry);
}

或者您可以直接push进入您的可观察数组（documentation）：

function dataRetrieved(data) {
    model.countries.removeAll();
    for (var i = 0; i<data.length; i++) {
        model.countries.push(data[i]);
    }
}

无法分配Json字符串数组

1 个答案: