How I use treeview checkchanged event without postback()?

protected void TreeView1_TreeNodeCheckChanged(object sender, TreeNodeEventArgs e)
        {
            if (e.Node.ChildNodes.Count > 0 && e.Node.Checked)
            {
                foreach (TreeNode childnode in e.Node.ChildNodes)
                {
                    childnode.Checked = true;
                }
            }
            else if (e.Node.ChildNodes.Count > 0 && !e.Node.Checked)
            {
                foreach (TreeNode childnode in e.Node.ChildNodes)
                {
                    childnode.Checked = false;
                }
            }
            else if (e.Node.ChildNodes.Count == 0 && e.Node.Checked)
            {
                e.Node.Parent.Checked = true;
            }
            else if (e.Node.ChildNodes.Count == 0 && Count_checkedChilds(e.Node.Parent) == 0)
            {
                e.Node.Parent.Checked = false;
            }
        }

        protected int Count_checkedChilds(TreeNode node)
        {
            int k = 0;
            foreach (TreeNode childnode in node.ChildNodes)
            {
                if (childnode.Checked == true)
                {
                    k++;
                }
            }
            return k;
        }

<pre><div class="col-xs-12 col-sm-12 col-md-12 col-lg-12">
          
        <asp:TreeView ID="TreeView1" runat="server" Width="189px" OnTreeNodeCheckChanged="TreeView1_TreeNodeCheckChanged">
            

        </asp:TreeView>
        
    </div>
    <script type="text/javascript">
        var btn = document.getElementById("Button1");
        function postBackByObject() {
            var o = window.event.srcElement;
            if (o.tagName == "INPUT" && o.type == "checkbox") {
                __doPostBack("", "");
                
            }
        }
    </script>