private void button1_Click(object sender, EventArgs e)
    {
        listView1.Columns.Add("No");
        listView1.View = View.Details;

        for (int i = 0; i < 9; i++)
        {
            // keep a temporary reference of the new nodes/items:
            ListViewItem lvi = listView1.Items.Add("Item " + i);
            TreeNode tn =  treeView1.Nodes.Add("Item " + i);
            // sotre them in the respective tags:
            lvi.Tag = tn;
            tn.Tag = lvi;
        }


    }

private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
    {
        if (e.Node.Tag != null)
            ((ListViewItem)(e.Node.Tag)).Checked = e.Node.Checked;
    }

    private void listView1_ItemChecked(object sender, ItemCheckedEventArgs e)
    {
        if (e.Item.Tag != null)
           ((TreeNode)(e.Item.Tag)).Checked = e.Item.Checked;
    }