/// <summary>
/// 假设treeview的name是 treeView1
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
{
if (e.Node.Nodes.Count > 0)
    {
foreach (TreeNode node in e.Node.Nodes)
        {
            node.Checked = e.Node.Checked;
        }
    }
}