When you tick any parent node, its child nodes also gets ticked automatically, you just need to copy them.
checkout below code, which gives you selected node of treeview
List<string> CheckedNames( System.Windows.Forms.TreeNodeCollection theNodes)
{
List<string> aResult = new List<string>();
if ( theNodes != null )
{
foreach ( System.Windows.Forms.TreeNode aNode in theNodes )
{
if ( aNode.Checked )
{
aResult.Add( aNode.Text );
}
aResult.AddRange( CheckedNames( aNode.Nodes ) );
}
}
return aResult;
}</string></string></string>