jqxDropDownList with knockout 无法绑定 selectedvalue

Question

我正在尝试将 jqxDropDownList 选定值与 ko.observable 绑定，但我不知道出了什么问题。它与常规的<select> 标签一起使用，但不适用于<div> 元素，正如我在下面的HTML 中所示。我需要用 jqwidgets 下拉列表替换 <select> 并按照工作代码中的说明进行相应的绑定。

ViewModel:

var viewModel = function(){
    var self = this;
    self.patternSelectedIndex = ko.observable(0);
    self.windowSelectedIndex = ko.observable(0);
    self.colorSelectedIndex = ko.observable(0);
    self.hardwareSelectedIndex = ko.observable(0);
    self.selectedMake = ko.observable();
    self.selectedType = ko.observable();

    self.makes = [
            {id:1, name: 'Northwoods Prestige', dimensions:true},
            {id:2, name: 'Forest Bay', dimensions:true},
            {id:3, name: 'Timberland', dimensions:true}
    ];
    self.types = [
            {id: 1, make:1, name:'Special Reserve 138', patterns:[{file:'FB_Classic', name:'FB Clasic'},{file:'FB_Long', name:'FB Long'},{file:'FB_Flush', name:'FB Flush'}], colors:[{file:'Brown', name:'Brown'},{file:'Oak', name:'Oak'},{file:'Cherry', name:'Cherry'},{file:'Green', name:'Green'}], windows:[{file:'Cascade', name:'Cascade'},{file:'LongPanel', name:'LongPanel'},{file:'Plain', name:'Plain'},{file:'Savanna', name:'Savanna'},{file:'Sunburst', name:'Sunburst'},{file:'Sherwood', name:'Sherwood'}], hardware:[{file:'hardware1', name:'Strap Hinge'},{file:'hardware2', name:'Door Stud'},{file:'hardware3', name:'Lift Handle'}]},
            {id: 2, make:1, name:'Special Reserve II', patterns:[{file:'SR_81', name:'SR 81'}], colors:[{file:'Almond', name:'Almond'},{file:'White', name:'White'}], windows:[{file:'Heritage', name:'Colonial'},{file:'Cascade', name:'Cascade'}], hardware:[{file:'hardware1', name:'Strap Hinge'},{file:'hardware3', name:'Lift Handle'}]},
            {id: 3, make:2, name:'TF 138', patterns:[{file:'Rec_Carraige', name:'Rec Carraige'}], colors:[{file:'Green', name:'Green'}, {file:'Sepia', name:'Sepia'}], windows:[{file:'Cathedral', name:'Cathedral'},{file:'Cascade', name:'Cascade'}], hardware:[{file:'hardware1', name:'Strap Hinge'},{file:'hardware3', name:'Lift Handle'}]},
            {id: 4, make:2, name:'TF II', patterns:[{file:'Raised_Carriage', name:'Raised Carriage'}], colors:[{file:'Almond', name:'Almond'}], windows:[{file:'Cathedral', name:'Cathedral'},{file:'Cascade', name:'Cascade'}], hardware:[{file:'hardware1', name:'Strap Hinge'},{file:'hardware3', name:'Lift Handle'}]},
            {id: 5, make:3, name:'RP 25', patterns:[{file:'FB_Classic', name:'FB Classic'}], colors:[{file:'Cherry', name:'Cherry'}], windows:[{file:'Cathedral', name:'Cathedral'},{file:'Cascade', name:'Cascade'}], hardware:[{file:'hardware1', name:'Strap Hinge'},{file:'hardware3', name:'Lift Handle'}]},
            {id: 6, make:3, name:'LP 25', patterns:[{file:'FB_Long', name:'FB Long'}], colors:[{file:'Green', name:'Green'}], windows:[{file:'Cathedral', name:'Cathedral'},{file:'Cascade', name:'Cascade'}], hardware:[{file:'hardware1', name:'Strap Hinge'},{file:'hardware3', name:'Lift Handle'}]}
    ];
    self.doorTypes = ko.computed(function(){
        return ko.utils.arrayFilter(self.types, function(item){
            return item.make === self.selectedMake();
        });
    });
    self.matchingTypes = ko.computed(function () {
        return ko.utils.arrayFilter(self.doorTypes(), function (item, index) {
            return item.id === self.selectedType();
        });
    }); 
};
var model = new viewModel();
ko.applyBindings(model);

（不工作）：在波纹管标记中，无法将值与 selectedMake 绑定，如工作示例 *2 所示。

<div id="make" data-bind="jqxDropDownList: {source: makes, autoDropDownHeight: true, height: 25, width: 200, displayMember : 'name'}"></div>

2* HTML（工作）：

<select id="make" class="form-control select pull-left" data-bind="options: makes, value: selectedMake, optionsText : 'name', optionsValue : 'id'"></select>

请看：jsfiddle.net/euto6vmj

Answer 1

看起来 jqxknockout 只支持通过数组索引选择项目，所以你需要添加一个函数来获取当前选择的索引。这里有两个函数与您的 selectedMake 和 selectedType 可观察对象同步以获取选定的索引：

self.selectedMakeIndex = ko.computed(function() { 
    return self.makes.map(function(e) { return e.id; }).indexOf(self.selectedMake());
});

self.selectedTypeIndex = ko.computed(function() { 
    return self.types.map(function(e) { return e.id; }).indexOf(self.selectedType());
});

每次你设置 selectedMake() observable 时，这些都会自动更新。只需在您的数据绑定中使用它：

<div id="make" data-bind="jqxDropDownList: {source: makes, autoDropDownHeight: true, height: 25, width: 200, displayMember : 'name', selectedIndex: selectedMakeIndex }"></div>

... 和类似的类型。

更新的 jsfiddle：http://jsfiddle.net/euto6vmj/1/