Find Control Deep Inside LoginView

Question

I have a login view control that I can find with findcontrol. Inside it is LoggedInTemplate->ul->li->ul->li->a. How can I find a? Here is sample code:

   <asp:LoginView runat="server" ViewStateMode="Disabled" ID="a">
          <LoggedInTemplate>
                 <ul class="nav navbar-centered navbar-nav" id="second-menu" role="menu" >
                     <li class="dropdown"><a runat="server" href="" class="dropdown-toggle" >AB</span></a>
                        <ul class="dropdown-menu">
                            <li><a runat="server" id="link">Link</a></li>

This works:

LoginView a = (LoginView)this.Master.FindControl("a");

But this doesn't:

HyperLink dashboardLink = (HyperLink)a.FindControl("link");

Answer 1

From the MSDN page of FindControl:

This method will find a control only if the control is directly contained by the specified container; that is, the method does not search throughout a hierarchy of controls within controls. For information about how to find a control when you do not know its immediate container, see How to: Access Server Controls by ID.

So you have to write your own recursive find method:

private Control FindControlRecursive(Control rootControl, string controlID)
{
    if (rootControl.ID == controlID) return rootControl;

    foreach (Control controlToSearch in rootControl.Controls)
    {
        Control controlToReturn = 
            FindControlRecursive(controlToSearch, controlID);
        if (controlToReturn != null) return controlToReturn;
    }
   return null;
}

Which you can use like this:

LoginView a = (LoginView)this.Master.FindControl("a");
HyperLink dashboardLink = (HyperLink)FindControlRecursive(a,"link");

or simply:

HyperLink dashboardLink = (HyperLink)FindControlRecursive(this.Master,"link");

But for that to work, you will have to use

<a runat="server" ID="link">Link</a>

as "ID" is case-sensitive, as far as I know.

Edit: According to this MSDN page, you can access that control by simply using it's name (ID).

When a control is not inside a naming container, you can get a reference to it by using the control's ID.

The article has sample code too.