public void CheckedFolder(TreeViewEventArgs e)
 {
     ExpandPlus exp = new ExpandPlus();
     exp.AfterExpand(e);
     TreeNode node = e.Node;
     if (node.Nodes.Count > 0)
     {
         foreach (TreeNode nod in node.Nodes)
         {
             nod.Checked = true;
         }
     }
 }
 public void OnAfterExpand(TreeViewEventArgs e)
 {
     ExpandPlus exp = new ExpandPlus();
     exp.AfterExpand(e);
 }