title: Get list of all checked nodes and its subnodes in treeview
body: <p>I have a treeview list check boxes and the list contains nodes, subnodes and in some cases subnode of subnode. When user check some items i want to get list of selected items.</p>
  
  <p>On this why I get only selcted items of main node:</p>
  
  <pre><code> foreach (System.Windows.Forms.TreeNode aNode in tvSastavnica.Nodes)
          {
              if (aNode.Checked == true)
              {
                  Console.WriteLine(aNode.Text);
              }
          }
  </code></pre>
  
  <p>How to travers through whole treeview and get checked items in subnodes?</p>