Request.Browser.IsMobileDevice Does not work in .Net 2.0

Question

User-939035612 posted

I have an old .net 2.0 site that I need to make mobile friendly but I can't set the mobile masterpage the way i do in .net 4. The code I have is as follows:

Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
        If Request.Browser.IsMobileDevice Then
            Me.MasterPageFile = "~/Site.Mobile.Master"
        End If
    End Sub

Answer 1

User-939035612 posted

I found a somewhat fix. I created a class called setmasterpage.vb with the following function

 Public Shared Function GetMaster(ByVal agent As Object) As String
        Dim UserAgent As String = agent.ToString
        Dim strMP As String = String.Empty
        If UserAgent.Contains("Phone") OrElse UserAgent.Contains("Android") OrElse UserAgent.Contains("Nexus") OrElse UserAgent.Contains("Mobile") Then
            strMP = "~/Site.Mobile.Master"
        Else
            strMP = "~/FinalMaster.Master"
        End If
        Return strMP
    End Function

Then on each Default.aspx.vb page I have the following:

Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
        Dim useragent = Request.ServerVariables("HTTP_USER_AGENT")
        Me.MasterPageFile = setmasterpage.GetMaster(useragent)
    End Sub

That works great on pages that do not have update panels. If I have an update panel I get a runtime error that says:

Server Error in '/' Application.

---

Unable to cast object of type 'ASP.site_mobile_master' to type 'ASP.finalmaster_master'.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidCastException: Unable to cast object of type 'ASP.site_mobile_master' to type 'ASP.finalmaster_master'.

Source Error:

Line 397: Line 398: Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init Line 399: AddHandler Master.ScriptManagerRef.Navigate, AddressOf ScriptManager1_Navigate Line 400: End Sub Line 401: Protected Sub ScriptManager1_Navigate(ByVal sender As Object, ByVal e As System.Web.UI.HistoryEventArgs)

Source File: C:\Users\me\Documents\Visual Studio 2010\Websites\mysite\videos\library.aspx.vb    Line: 399

Stack Trace:

[InvalidCastException: Unable to cast object of type 'ASP.site_mobile_master' to type 'ASP.finalmaster_master'.] videos_library.get_Master() +74 videos_library.Page_Init(Object sender, EventArgs e) in C:\Users\me\Documents\Visual Studio 2010\Websites\mysite\videos\library.aspx.vb:399 System.Web.UI.Control.OnInit(EventArgs e) +99 System.Web.UI.Page.OnInit(EventArgs e) +12 System.Web.UI.Control.InitRecursive(Control namingContainer) +333 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +378

Answer 2

User-939035612 posted

Fixed that by removing Master virtualpath from the page'

And adding 

Public ReadOnly Property ScriptManager1() As ScriptManager
        Get
            Dim ScriptManagerRef As ScriptManager = CType(Page.Master.FindControl("ScriptManager1"), ScriptManager)
            Return ScriptManagerRef
        End Get
    End Property
    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        Dim ScriptManagerRef As ScriptManager = CType(Page.Master.FindControl("ScriptManager1"), ScriptManager)
        AddHandler ScriptManagerRef.Navigate, AddressOf ScriptManager1_Navigate
    End Sub