I have a Treeview acting as a menu on the left side of my web app pages.  Below this I have a simple LinkButton that I want to alternate between "Open Menu" and "Close Menu".  Both the Treeview and the LinkButton sit within an AJAX Update Panel but for both the Update Panel and the LinkButton have EnableViewState="true".

What I'm puzzled by is that in the LinkButton's event handler the text of the button always seems to contain "Open Menu", even though I can clearly see that it shows "Close Menu" on the screen.  As such, I can't properly toggle the menu open/close/open/close etc.

What more do I need to do to be able to check the text of the LinkButton to determine whether the Treeview is expanded or collapsed?

Robert 

Hi,

Base  on your description, do you want to use the linkbutton to expand or collapse menu items, and change the linkbutton's text according to menu's status at the same time, right?

Below is my test code, hope it helps:

<asp:TreeView ID="TreeView1" runat="server" DataSourceID="SiteMapDataSource1" OnTreeNodeExpanded="TreeView1_TreeNodeExpanded" OnSelectedNodeChanged="TreeView1_SelectedNodeChanged" OnTreeNodeCollapsed="TreeView1_TreeNodeCollapsed" ShowLines="True">
                    </asp:TreeView>
                    <asp:LinkButton ID="lbClose" runat="server" OnClick="lbClose_Click">Close Menu</asp:LinkButton>

The codebehind of the linkbutton:

 protected void lbClose_Click(object sender, EventArgs e)
    {

        TreeNode tn = this.TreeView1.Nodes[0];
        if (tn.Expanded == true)
        {
            this.TreeView1.CollapseAll();

            this.lbClose.Text = "open Menu";
        }
        else
        {
            this.TreeView1.ExpandAll();

            this.lbClose.Text = "Close Menu";
        }
    }

Thanks, Amanda.  Because of no response to this thread to date I posted the msg in another one.  In it, I eventually came up with an answer: http://forums.asp.net/p/1188354/2035485.aspx#2035485

P.S. In my testing I found that the nodes count = 0.  As such, the CollapseAll() didn't work, though surprisingly the ExpandAll() did.

Robert 

Hi,

I use the TreeView1.Nodes[0] in oeder to find the root node, if you know what the root node is, you can use the findnode method, like below:

TreeNode tn = this.TreeView2.FindNode("Home");// The root node's text is Home

So you can adjust the status of the root, then expand/collapse menu control.

 protected void lbClose_Click(object sender, EventArgs e)
    {

    TreeNode tn = this.TreeView2.FindNode("Home");// find the root node of the treeview

        if (tn.Expanded == true)// adjust the rootnode whether is expanded
        {
            this.TreeView1.CollapseAll();

            this.lbClose.Text = "open Menu";
        }
        else
        {
            this.TreeView1.ExpandAll();

            this.lbClose.Text = "Close Menu";
        }
    }

Hope it helps.

Amanda,

I'm glad it's working for you.  On my system, in the Click event, which occurs before the Data Binding, there are 0 nodes in the tree.  I'm guessing that you must be populating your tree in a different way.

I have a related question for you: Envision a tree in any state (ie. maybe all the nodes are closed, maybe they're all open, maybe some are open and some are closed).  This is the way the treeview, which serves as the menu on the left side of my master page works.  Now, when I jump from page to page to page, the tree always closes up again.  I'm not surprised, because the tree is being binded again.

But might you know a way around this so that it remains the same and thus provides a consistent appearance for the user?

Robert