private void treeView1_AfterCheck(object sender, TreeViewEventArgs e){    if (e.Action != TreeViewAction.ByMouse)        return;    SetParentNode(e.Node);    SetChildNode(e.Node);}private void SetParentNode(TreeNode node){    if (node.Level > 0)    {        node.Parent.Checked = true;        SetParentNode(node.Parent);    }}private void SetChildNode(TreeNode node){    foreach (TreeNode childNode in node.Nodes)    {        childNode.Checked = node.Checked;        if (node.Nodes.Count > 0)SetChildNode(childNode);    }}