I was working on a TreeView bound to a SiteMap control. Due to a space constraint while displaying the TreeView, I had to save as much space as I could while displaying my TreeView. Now by default, when a TreeView is generated, the Parent Root Nodes have a whitespace indent as visible below
When the TreeView gets rendered, ASP.NET generates a number of HTML Table tags to format it’s layout. So to remove the whitespace before each parent node, just use the following CSS
.tv table tbody tr td:first-child
where tv is the CssClass applied to the TreeView.
<asp:TreeView ID="TreeView1" runat="server"
The resultant output is as shown below with the extra whitespace removed: