从母版页的背后代码（vb.net）更改母版页上的标签文本

Question

I am creating a badge notification in a navigation list item. I would like to be able to update the label from the code behind of the master page. I am stuck here is my code.

<asp:RoleGroup Roles="Admin">
                                <ContentTemplate>
                                    <ul class="nav navbar-nav navbar-right">
                                        <%--<li><a runat="server" href="~/">Home</a></li>--%>
                                        <li class="dropdown">
                                            <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Submissions<span class="caret"></span></a>
                                            <ul class="dropdown-menu" role="menu">
                                                <li><a runat="server" href="Submissions">Submissions</a></li>
                                                <li><a runat="server" href="SubmissionEmails">Emails</a></li>
                                                <li><a runat="server" href="SubmissionEmailTemplate">Email Template</a></li>
                                            </ul>
                                        </li>
                                        <li><a runat="server" href="Faults">Faults</a></li>
                                        <li class="dropdown">
                                            <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Reporting<span class="caret"></span></a>
                                            <ul class="dropdown-menu" role="menu">
                                                <li><a runat="server" href="CompanyDeclaration">Declaration</a></li>
                                                <li><a runat="server" href="CompanyDeclarationSummary">Summary</a></li>
                                                <li><a runat="server" href="CompanyTemplate">Template</a></li>
                                            </ul>
                                        </li>
                                        <li class="dropdown">
                                            <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false"><img src="/images/person.png"> <%: Context.User.Identity.Name()%> <label class="badge badge-danger" ID="Count" runat="server">5</label><span class="caret"></span></a>
                                            <ul class="dropdown-menu" role="menu">
                                                <li><a runat="server" href="~/Admin/FaultCodeRules">Fault Code Rules</a></li>
                                                <li><a <a runat="server" href="~/Admin/Smelters">Standard Smelters</a></li>
                                                <%--<li><a href="#">Back Flush</a></li>--%>
                                                <%--<li><a runat="server" href="SalesData">Sales Data</a></li>--%>
                                                <%--<li><a runat="server" href="Vendor">Vendor</a></li>--%>
                                                <%--<li><a runat="server" href="Usage">WebSite Usage</a></li>--%>
                                                <li class="divider"></li>
                                                <li class="dropdown-header">Admin Tools</li>
                                                <li><a runat="server" href="~/Admin/PendingRegistrations">Pending Registrations <label class="badge badge-danger" ID="UCount" runat="server">13</label></a></li>
                                                <li><a runat="server" href="~/Admin/AssignRoles">Assign Roles</a></li>
                                                <li><a runat="server" href="~/Admin/AddFactory">Add New Factory</a></li>
                                                <li><a runat="server" href="~/Admin/Register">Register User</a></li>
                                                <li><a runat="server" href="~/Admin/SwitchUser">View as another Factory</a></li>
                                                <li class="divider"></li>
                                                <li><a runat="server" href="~/Account/Manage" title="Manage your account">Manage Your Account</a></li>                                              
                                                <li>
                                                   <asp:LoginStatus runat="server" LogoutAction="Redirect" LogoutText="Log off" LogoutPageUrl="~/" OnLoggingOut="Unnamed_LoggingOut" />
                                               </li>
                                            </ul>
                                        </li>
                                        <li>
                                            <a runat="server" href="Default"><img alt="Home" src="/images/Home-24.png"></a>
                                        </li>
                                    </ul>
                                </ContentTemplate>
                            </asp:RoleGroup>

  Snippet 

<li><a runat="server" href="~/Admin/PendingRegistrations">Pending Registrations <asp:Label class="badge badge-danger" ID="Label1" runat="server" /></a></li>

Here is the code in my code behind file.

Dim connectionString As String = ConfigurationManager.ConnectionStrings("DefaultConnection").ConnectionString
Dim con As New SqlConnection(connectionString)
Dim cmd As SqlCommand = New SqlCommand
cmd.Connection = con
con.Open()
cmd.CommandText = "Select Count(*) From User_Register"
Dim UserCount = cmd.ExecuteScalar()
con.Close()
label1.text = UserCount

Please Help

Answer 1

Your LoginView is a templated control and as such, the controls cannot be accessed as you're trying. FindControl normally works, but in this case, only searches direct child controls.

So you might do something like this (replacing MyLoginViewID with your LoginView's ID:

Dim label as Label = CType(FindControlRecursive(MyLoginViewID, "Label1"), Label)
label.Text = UserCount.ToString()

Below is a method I've used before, and my answer was inspired by this answer

''' <summary>
    ''' Recursively loops through all containers in a control looking for the specified control.
    ''' </summary>
    ''' <param name="callingControl"></param>
    ''' <param name="controlId"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function FindControlRecursive(ByVal callingControl As System.Web.UI.Control, ByVal controlId As String) As System.Web.UI.Control

        If callingControl Is Nothing Then Return Nothing

        Dim ctrl As Control = callingControl.FindControl(controlId)

        If ctrl Is Nothing Then
            For Each child As Control In callingControl.Controls
                ctrl = FindControlRecursive(child, controlId)
                If ctrl IsNot Nothing Then Exit For
            Next
        End If

        Return ctrl

    End Function

Answer 2

I found a solution

Dim lv As LoginView = DirectCast(FindControl("myLoginView"), LoginView)
                Dim ln As Label = DirectCast(lv.FindControl("Count"), Label)
                ln.Text = UserCount.ToString