title: datagrid will render the data twice
body: <p>I used the DataGrid to display data, but I found a wizard case that will render the data twice.</p>
  
  <p>Details are below:</p>
  
  <ol>
  <li>Click the "browse" button, then it will send a request to the server;</li>
  <li>Server returns the JSON format data</li>
  <li><p>Use the alert to debug in DataGrid like:</p>
  
  <pre><code>loadFilter: function (data) {
              //alert(JSON.stringify(data));
              alert(data.rows.length);
              if (data.rows.length == 0) {
                  //alert('读取有问题，重新填充');
                  $(selector).datagrid("load");
                  return $(selector).datagrid("getData");
              }
              return data;
          },
  </code></pre></li>
  <li><p>The alert then occurs twice, one by one.</p></li>
  </ol>