private void trvDBBinding_AfterCheck(object sender, System.Windows.Forms.TreeViewEventArgs e)
{
    if( e.Action != TreeViewAction.Unknown )
    {
        //Event call by mouse or key-press
        SetNodeCheckStatus( e.Node, e.Node.Checked );
    }
}

private void SetNodeCheckStatus( TreeNode tn, bool Checked )
{
    if( tn == null ) return;
    // Check children nodes
    foreach (TreeNode tnChild in tn.Nodes)
    {
        tnChild.Checked = Checked;
        SetNodeCheckStatus( tnChild, Checked );
    }
    // Set parent check status
    TreeNode tnParent = tn;
    int nNodeCount = 0;
    while( tnParent.Parent != null )
    {
        tnParent = (TreeNode)(tnParent.Parent);
        nNodeCount = 0;
        foreach( TreeNode tnTemp in tnParent.Nodes )
            if( tnTemp.Checked == Checked )
                nNodeCount++;
        if( nNodeCount == tnParent.Nodes.Count )
            tnParent.Checked = Checked;
        else
            tnParent.Checked = false;
    }
}