title: Access list elements with knockout
body: <p>I have a list with 2 images per line, after filling the list with my datasource, I need to set one of the images with "visible = false" depending on the user's choice, I am not able to access the list elements to set one of the images = false</p>
  
  <p>list html</p>
  
  <pre><code>            &lt;div data-bind="dxList: {items: listItems, dataSource: AdataSource, pullRefreshEnabled: true }" id="lxDados"&gt;
              &lt;div data-options="dxTemplate : { name: 'item' } " id="dxtemp"&gt;
  
                  &lt;div class="us-linha-img"&gt;
                      &lt;span class="dx-icon-map icon us-itens-linha"&gt;&lt;/span&gt;
                      &lt;span class="us-itens-linha" data-bind="text: evento"&gt;&lt;/span&gt;
                  &lt;/div&gt;
  
                  &lt;img id="imcodb" data-bind="attr: { src: $data.codbar, alt: $data.codbar }" /&gt;
                  &lt;br /&gt;
                  &lt;img id="imcodbqr" data-bind="attr: { src: $data.codbarqr, alt: $data.codbar }" /&gt;
  
              &lt;/div&gt;
          &lt;/div&gt;
  </code></pre>
  
  <p>js file
  In this function, after loading the list with my datasource, I need to scroll through the list and set one of the "img" to visible = true or false.</p>
  
  <pre><code>function trocarCodBar(m) {
  AdataSource = loadDataSource();
  viewModel.AdataSource(AdataSource);
  //done...
  for (var i = 0; i &lt; viewModel.listItems().length; i++) {
      if(m=='bar')
      //set &lt;img imcodb or imcodbqr visible false or true.
  }}
  </code></pre>
  
  <p>view</p>
  
  <pre><code>var viewModel = {
  bloadpanel: ko.observable(false),
  AdataSource: null,
  listItems: ko.observableArray(),
  trocarCodBarBar: function () {
      trocarCodBar("bar");
  },
  trocarCodBarQR: function () {
      trocarCodBar("qrc");
  },
  viewShown: function () {
      //alterar valores na inicialização
  },
  title: ko.observable("Pedido: " + params.id)};
  viewModel.AdataSource = AdataSource;
  return viewModel;
  </code></pre>