binding knockout dropdown in foreach

Question

I have a dropdown inside a foreach

 <tbody data-bind="foreach:  Details">
 <tr style="border: none">
 <select style="width: 130px" 
         data-bind=" optionsCaption: 'Choose...', 
          options: $data.filteredList, optionsText: 'number',
          optionsValue: 'id'">
 </select>
 </tr>

This binding does not seem to work. When I debug I can see that the filter is updating but I never get any thing in the dropdown.

I added this:

<pre data-bind="text: ko.toJSON($data, null, 2)"></pre>

This is the result:

{
  "Seed": 1,
  "filteredList": [
    {
      "id": "a",
      "number": "12"
    },
    {
      "id": "b",
      "number": "12"
    } 
}

And I can see that the filter values are changing.

Why would the dropdown be empty?

Answer 1

只要改变$data.filteredList至$root.filteredList的结合，如果filteredList是其成员的ModelView 。