title: how can i assign ObjectListView Checkbox Value
body: <p>I am using <code>ObjectListView</code>, and I am dealing with Checkboxes in it. In the documentation of the <code>ObjectListView</code> it is mentioned that i can use this code to set the checkbox value:</p>
  
  <pre><code>foreach (OLVListItem olvi in objectListView1.SelectedItems) 
     olvi.Checked = !olvi.Checked;
  </code></pre>
  
  <p>But i cant use the <code>OLVListItem</code>. What namespace should i add to the project? And what is the difference between setting the checkbox value by using this way and setting putter delegate?</p>