使用requirejs for knockout和knockout.simpleGrid时，ko是未定义的错误

Question

当使用requirejs加载依赖项时，我在knockout.simpleGrid 3.0中得到ko是未定义的错误。这是我的require.config.js

var require = {
    baseUrl: "/",
    paths: {
        "bootstrap": "Scripts/lib/bootstrap/bootstrap",
        "crossroads": "Scripts/lib/crossroads/crossroads",
        "jquery": "Scripts/lib/jquery/jquery-2.1.4",
        "knockout": "Scripts/lib/knockout/knockout-3.3.0",
        "koSimpleGrid": "Scripts/lib/knockout/knockout.simpleGrid.3.0",
        "koProjections": "Scripts/lib/knockout/knockout-projections",
        "signals": "Scripts/lib/crossroads/signals",
        "hasher": "Scripts/lib/crossroads/hasher",
        "text": "Scripts/lib/require/text"
    },
    shim: {
        "bootstrap": { deps: ["jquery"] },
        "koSimpleGrid": { deps: ["knockout"] }
    }
}

这是导致错误的代码。

 ko.simpleGrid = {
        // Defines a view model class you can use to populate a grid
        viewModel: function (configuration) {
            this.data = configuration.data;
            this.currentPageIndex = ko.observable(0);
            this.pageSize = configuration.pageSize || 5;

            // If you don't specify columns configuration, we'll use scaffolding
            this.columns = configuration.columns || getColumnsForScaffolding(ko.unwrap(this.data));

            this.itemsOnCurrentPage = ko.computed(function () {
                var startIndex = this.pageSize * this.currentPageIndex();
                return ko.unwrap(this.data).slice(startIndex, startIndex + this.pageSize);
            }, this);

            this.maxPageIndex = ko.computed(function () {
                return Math.ceil(ko.unwrap(this.data).length / this.pageSize) - 1;
            }, this);
        }
    };

我尝试将ko作为参数传递给knockout.simpleGrid但仍然在此行中给出了相同的错误

this.currentPageIndex = ko.observable(0);