Heey,

We have a problem with a tabview not rendering its ScrollingMenu component properly. Our structure is like thus: 

We have a MasterPage with the TabView on it:

<cc1:TabView runat="server" ID="tabView" AutoResize="false" Width="800px" Height="400px" />

Then we have several aspx pages with register in their OnInit Event which tabs needs to be created and which user controls in the form of a subform usercontrol needs to be added to it, example:

protected override void OnInit(EventArgs e)

{

            base.OnInit(e);

            Master.TabControl.RegisterSubFormTab(EventsPane,EventsForm, "Events");

            Master.TabControl.RegisterSubFormTab(EmployeePane, EmployeeForm, "Employees");

 }

The function itself adds the tab to be created in a list.

On the OnLoad() event of the MasterPage another function is called that loops through the list and adds the tabs to the tab view like so:

          private void AppendTab(AdminTab tab)

        {

            tab.Control.TabPage = UmbracoTabComponent.NewTabPage(tab.Name);

            tab.Control.TabPage.HasMenu = true;

            tab.Control.TabPage.Controls.Add(tab.Pane);

        }

There is another piece of code that add adds buttons to the menu:

private void CreateMenuButton(out ImageButton btn, ImageClickEventHandler handler, string toolTip, string imgUrl, bool causesValidation, string validationgroup = null)

        {

            btn = TabPage.Menu.NewImageButton();

            btn.ID = TabPage.Menu.ClientID + "_" + toolTip;

            btn.Click += new ImageClickEventHandler(handler);

            btn.ToolTip = toolTip;

            btn.AlternateText = toolTip;

            btn.ImageUrl = imgUrl;

            btn.Visible = false;

            btn.ValidationGroup = validationgroup;

            btn.CausesValidation = causesValidation;

        }

Now when the code is run. The tabs are and the pane with its controls are shown like they are supposed to. Only one slight problem: The Menu is not rendered properly. There are no buttons visible and even the scrolling arrows on either side of the menu are not visible. The strange thing is when a postback to the server is performed the menu IS rendering properly and the buttons work just fine.

After fiddling around for a day i cant figure out why the menu is not rendered properly the first time. It can't be that hard to build a tabpage dynamically.