javascript - 未捕获的类型错误 : Object function () has no method items

Question

我正在将 json 数据绑定(bind)到 ul 标记中。它表明发生了错误。代码如下:

<div id="newdiv" data-bind="visible: selectedSection() === 'ulClass', stopBinding: true ">
    <ul id="ulClass" data-bind="template: { name: 'templatesSample', foreach: items}">
        <script id="templatesSample" type="text/html">
            <li><span data - bind = "text:name" > </span>
            </li>
        </script>
    </ul>
</div>

View 模型

function names(firstnames) {
    this.name = ko.observable(firstnames);
}

var mappedData;
var viewmodel;

$(document).ready(function () {
    ko.bindingHandlers.stopBinding = {
        init: function () {
            return {
                controlsDescendantBindings: true
            };
        }
    };
    ko.virtualElements.allowedBindings.stopBinding = true;

    viewmodel = function () {
        items: ko.observableArray([]);
    };


    var namesOfPeople = '[{"Firstnames":"john"},{"Firstnames":"peter"},{"Firstnames":"mary"}]';
    var dataFromServer = ko.utils.parseJson(namesOfPeople);
    mappedData = ko.utils.arrayMap(dataFromServer, function (item) {
        return new names(item.Firstnames);
    });

    viewmodel.items(mappedData);

    ko.applyBindings(viewmodel, document.getElementById("ulClass"));
});

它在控制台中显示以下错误:

Uncaught TypeError: Object function ()
    {
         items:ko.observableArray([]);

    } has no method 'items' 

如何解决该问题？请提出解决方案。

谢谢

Answer 1

您需要决定是将虚拟机初始化为对象还是使用构造函数。

这是两者的组合，我认为在语法上大多是无效的:):

viewmodel = function()
{
    items:ko.observableArray([]);
};

所以要么这样做:

viewmodel = {
                items:ko.observableArray([]);
            };

或者这个:

var VM=function() {
                     this.items = ko.observableArray([]);
                };

var viewModel = new VM();