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I have 2 dropdowns. When i select value from one dropdown it will load values in another dropdown depending upon what is selected.

Here is my html code

<select data-bind="options: filters, value: filter"></select>

<select data-bind="options: filteredItems, optionsText: 'name'"></select>

Here is my knockout code

var ViewModel = function(data) {
var self = this;
self.filters = ko.observableArray(data.filters);
self.filter = ko.observable('');
self.items = ko.observableArray(data.items);
self.filteredItems = ko.computed(function() {
    var filter = self.filter();
    if (!filter || filter == "None") {
        return self.items.slice(0, 6);
    } else {
        return self.items.slice(2);
    }
  });
};


  var initialData = {
     filters: ["None", "Old", "New", "Super"],
       items: [{ name: "Corvette", type: "Old"},
       { name: "Charger", type: "Old"},
       { name: "Prius", type: "New"},
       { name: "Magnum", type: "New"},
       { name: "McLaren", type: "Super"},
       { name: "Saleen", type: "Super"}]


   ko.applyBindings(new ViewModel(initialData));

When i select Type as None then it selects all Cars and if i select type other than None then it should only select "Charger" and "Magnum"

Here is the link to fiddle

4

1 回答 1

1

首先，如果要返回所有项目，只需 return self.items()，不需要切片。如果您想返回匹配过滤器的项目，这应该有效：

self.filteredItems = ko.computed(function() {
    var myFilter = self.filter();
    if (!myFilter || myFilter == "None") {
        return self.items();
    } else {
        var tempArray = [];
        for(i=0; i<self.items().length; i++) {
            if(self.items()[i].type == myFilter) {
                tempArray.push(self.items()[i]);
            }
        }
        return tempArray;
    }
});

检查工作小提琴。

如果你只想在这里选择“充电器”和“马格南”：

self.filteredItems = ko.computed(function() {
    var myFilter = self.filter();
    if (!myFilter || myFilter == "None") {
        return self.items();
    } else {
        return [ self.items()[1], self.items()[3] ];
    }
});
于 2013-04-25T17:59:15.337 回答