绑定敲除foreach时的表行号

Question

我有一个带有标题的表(#,用户名,用户姓),当用户从复选框列表中选择用户名时,正在执行淘汰foreach循环以添加行.这是我的小提琴.

HTML

<div>
    <table class="table table-bordered">
       <thead>
           <th>#</th>
           <th>User Name</th>
           <th>User Surname</th>
       </thead>
       <tbody data-bind="foreach: users">
           <tr data-bind="if: userselected">
               <!-- The table row number -->
               <td data-bind="text: $index() + 1"></td>
               <td data-bind="text: username"></td>
               <td data-bind="text: usersurname"></td>
           </tr>
       </tbody>
   </table>
</div>

JS

var myViewModel = {
     users: ko.observableArray([{
         username: 'Name 1',
         usersurname: 'Surname 1',
         userselected: ko.observable(false)
     }, {
         username: 'Name 2',
         usersurname: 'Surname 2',
         userselected: ko.observable(false)
     }, {
         username: 'Name 3',
         usersurname: 'Surname 3',
         userselected: ko.observable(false)
     }])
 };

 $(document).ready(function () {
     //Bind View model
     ko.applyBindings(myViewModel);
 });

当用户选择用户1和3时,问题就出现了$ index()+ 1不适用于行号.

我需要一种动态设置行号的方法.

提前致谢.

Answer 1

我会创建一个计算的observable,我在那里进行过滤.然后$index()将提供正确的rownumbers:

因此,selectedUsers为您的新属性添加myViewModel:

myViewModel.selectedUsers = ko.computed(function () {
     return ko.utils.arrayFilter(myViewModel.users(), function (item) {
         return item.userselected();
     });
 });

然后在你的表中绑定它:

<tbody data-bind="foreach: selectedUsers">
        <tr>
            <!-- The table row number -->
            <td data-bind="text: $index() + 1"></td>
            <td data-bind="text: username"></td>
            <td data-bind="text: usersurname"></td>
        </tr>
</tbody>

演示JSFiddle.