hi folks,

I have some problems regarding the TreeView control.

1. When AutoPostBack is set to true, all events (Expand/Collapse/SelectedIndexChange) cause a postback. But I only want the event SelectedIndexChange to be posted back, because Expand and Collapse needn't be handled on server. What should I do to disable Expand/Collapse to be posted back?

2. Can I add LinkButtons or other Web Controls into a TreeNode? When the user select a TreeNode, I want a command to be issued, NOT a url to be opened. To do this, I tried to embed LinkButtons to TreeNodes but TreeNode isn't inherited from System.Web.UI.Control so I can't write code like this:

LinkButton button = new LinkButton();
... (configure the button)
TreeNode node = new TreeNode();
node.Controls.Add(button);

I think that if TreeNode inherits System.Web.UI.Control, it would be much more elegant than the current implementation.

3. there are multiple dynamically created TreeViews on a single page. When users select a TreeNode in one of these TreeViews, the event SelectedIndexChange only contains the index of new/old nodes, how could I know which TreeView the selected TreeNode belongs to?
If the event SelectedIndexChange also contains the ID of the selected TreeNode (but it doesn't), the problem can be solved easily.


btw: I had requested these new features in another post
http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=300392

I have had the same problem.
I managed to find a workaround, not very elegant though. Code is in C#

in .aspx
make Treeview1.AutoPostback = false

add an hidden input field (tbSelectedNode), don't forget to make it RunAtServer
add a asp:Button (btnPost), I made this 1px high 1px wide so you can't see it

add a javascript function in the HEAD section for the events to handle
<script type="text/javascript">
function nodepostback()
{
var postback = document.getElementById('btnPost');
var hidden = document.getElementById('tbSelectedNode');
var treeview = document.getElementById('tvMeterGroups');
if(hidden != null && treeview != null)
{
if(*** enter your condition for posting here, if you want one ***)
{
hidden.value = treeview.selectedNodeIndex;
postback .click();
}
}
return false;
};
</script>

in code behind .aspx.cs
add the handlers for the events you want to handle, in the Page_Load like this:
Treeview1.Attributes.Add("onselectedindexchange", "javascript:nodepostback();");

add a page private static string variable:
private static string strSelectedNode = "";

add a click handler for the button
private void btnPost_Click(object sender, System.EventArgs e)
{
strSelectedNode = tbSelectedNode.Value;
....
....
}

add PreRender for the treeview, to ensure the selection gets made
private void Treeview1_PreRender(object sender, System.EventArgs e)
{
Treeview1.SelectedNodeIndex = strSelectedNode;
}



The above worked for me when all I wanted was 'onselectedindexchange' postback.

I tried 'return false' handlers for the other events, when I had AutoPoasback=true, but that caused the control to lose collapsed/expanded info.
I tried to remove attributes for the events I didn't want posted back in PreRender but that didn't remove them when I viewed source.
This was all I could get to work.

I hope this may help others who have similar problems.

Hi!

I read in your post that you've added multiple treeviews in a page successfully. I am using treeview control in my Sharepoint Webparts (individual application which you can add in a page), i have created multiple webparts which uses the treeview to display different datas. I have try add multiple webparts in one page. But as soon as I add another webpart with treeview control in it. one of them stops displaying treeview!!! it's really wierd. could you please help me out in this one? what am i doing wrong? ie. how you are diming the treeivew and instanciating the control etc.. proxy settings.. etc.

Any help in this will be much appriciated.

Regards,
Nilesh

 hi

I could not find any attribute like Autopostback for asp.net treeview control.

To disable Expand/Collapse to be posted back , check if its EnableClientScript  attribute is set to true.

To add LinkButtons or other Web Controls into a TreeNode, please refer this:

http://forums.asp.net/p/1372883/2876414.aspx

 hope this helps......