I've tried the TreeView in a project template with CSS Friendly.

Here is the very simple code:

 <asp:TreeView ID="employeeTreeView" runat="server" ShowLines="True"></asp:TreeView>

There is a code in Page_Load method that populates the componet above.

After it, it's automatically called the method

System.IndexOutOfRangeException was unhandled by user code
  Message="O ?ndice estava fora dos limites da matriz."
  Source="App_Code.z3zjkoru"
  StackTrace:
       em CSSFriendly.TreeViewAdapter.ExpandToState(TreeNodeCollection nodes, String state) na d:\sites\estudo\aspx\asp.net.2.0\DataBaseAccessing\App_Code\Adapters\TreeViewAdapter.cs:linha 681
       em CSSFriendly.TreeViewAdapter.OnLoad(EventArgs e) na d:\sites\estudo\aspx\asp.net.2.0\DataBaseAccessing\App_Code\Adapters\TreeViewAdapter.cs:linha 177
       em System.Web.UI.Control.LoadRecursive()
       em System.Web.UI.Control.LoadRecursive()
       em System.Web.UI.Control.LoadRecursive()
       em System.Web.UI.Control.LoadRecursive()
       em System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

what's the problem?

Regards!

This is an interesting problem.  It sounds like a bug.  Let's try to figure out what's going on and develop a fix that you can use right away.

I've looked over the code and I'm still confused how you could have gotten into this state.  Let me ask a few very direct questions:

1. Does your page crash when it loads the first time?  Or, it the crash only happening when the page posts back?
2. Does your code behind (Page_Load method) set the tree's ShowExpandCollapse property?  (It might be helpful to see some of you code from Page_Load.)
3. Is the tree expanded at all (via the code in your Page_Load)?

Sorry that I don't have an immediate answer for you (just lots of questions). Hopefully if I can get a bit more data I can help later today.

I would like to add one more point to what Russ asked -

4.Can you translate what this message is

 System.IndexOutOfRangeException was unhandled by user code
  Message="O ?ndice estava fora dos limites da matriz."

The message is saying that an index is out of the allowable range.  I believe this is happening when the following line is executed in the TreeVIew adapter:

bool bExpand = (state[0] == 'e');

The variable "state" is a character string from which I'm trying to get the zeroth (first) character... in order to determine if it is the letter "e."  However, if "state" is empty (no length) then it isn't legitimate to access its first letter.  If you try (like I do in the statement above) and the string is empty you get the message shown in this posting (albeit in the appropriate language for you).

The question then hinges on why "state" ended up not having any characters in it.  Normally, such is not the case... or at least I certainly didn't anticpate that that would happen at that point in the code.  So you need to look upward in the code to see how "state" gets established before being passed to this method (that is the one that's crashing).  That analysis led to the questions I was asking earlier.

Nonetheless, I'd prefer that the author of this posting add a direct translation of this error message, too, since my linguistic skills are certainly limited and suspect! Meanwhile, interested readers might want to go to http://translate.google.com/translate_t, enter the phrase we want translated and choose (from the dropdown) that you want the translation between "Portuguese to English."  This approximation yields a translation of "The index was of the limits of the matrix."