knockoutjs订阅不工作?

时间:2013-11-10 06:00:14

标签: javascript knockout.js

我正在使用knockoutjs,我是新手。我想根据下拉列表选择值更改模型数据。所以在我的AppModel中,我订阅了我想要更改的数组。但它不起作用?这是我的代码:

var filteredStocks  = [];
function viewModel(model) {
        this.isGeneral = ko.observable(model.generalStockEnabled);
        this.stocks = ko.observable();;
        if (model.generalStockEnabled === true)
        {
            filteredStocks = $.grep(model.stocks, function (v) {
                return v.sourceID === -1;
            });
        }
        else
        {
            filteredStocks = $.grep(model.stocks, function (v) {
                return v.sourceID !== -1;
            });
        }
        // If drop downlist changed
        var dropDownListSelectedValue = $('#enableGeneratInventorydl :selected').val();
        this.stocks.subscribe(function () {
            if (dropDownListSelectedValue === "True") {
                filteredStocks = $.grep(model.stocks, function (v) {
                    return v.sourceID === -1;
                });
                this.stocks(filteredStocks)
                this.isGeneral(true);
            }
            else
            {
                filteredStocks = $.grep(model.stocks, function (v) {
                    return v.sourceID !== -1;
                });
                this.stocks(filteredStocks)
                this.isGeneral(false);
            }
        }, this);

        this.stocks = ko.observableArray(filteredStocks);

当我更改下拉列表值时。股票价值保持不变?

感谢任何帮助。

1 个答案:

答案 0 :(得分:9)

出现问题是因为您将stocks变量重新分配给另一个observable。 所以你先做:

this.stocks = ko.observable();

然后订阅此可观察对象。但后来你做了:

this.stocks = ko.observableArray(filteredStocks);

这会将stocks与另一个观察者相关联。订阅将针对原始观察,即第一次分配的观察。 请参阅此小提琴,以获得更短的示例:http://jsfiddle.net/9nGQ9/2/

解决方案是替换this.stocks = ko.observable();

this.stocks = ko.observableArray();

并替换this.stocks = ko.observableArray(filteredStocks);

this.stocks(filteredStocks);