set masterpage file dynamically- c#

The only way it works is when I change it manually to:

<%@ Page Title="" Language="C#"  AutoEventWireup="false"    MasterPageFile="~/MasterPage.master" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

or 

<%@ Page Title="" Language="C#"  AutoEventWireup="false"    MasterPageFile="~/MasterPage2.master" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

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To do this dynamically, from the a control on the master page, I open a page using:

Response.Redirect("Default2.aspx", false);    //<-- have tried true also

and in the Default2.aspx.cs I have:
public partial class Default2 : System.Web.UI.Page
{
   protected void Page_Load(object sender, EventArgs e)
   {
       
    }
    protected void Page_Preint(object sender, EventArgs e)
    {
        MasterPage myMaster=Master as MasterPage;
      Label lbl = (Label)myMaster.FindControl("lblCmdOpt");
        if (lbl.Text == "f123")
        {
        MasterPageFile =  "~//MasterPage.master";
       }
        else
       {
            MasterPageFile = "~//MasterPage2.master";
        }
    }
}

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But the problem is Page_Preint doesn't fire.

Question: How can I change the masterPage dynamically?

Thank you.
LVL 34
Mike EghtebasDatabase and Application DeveloperAsked:
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Daniel Van Der WerkenIndependent ConsultantCommented:
Could be the issue is simply that you're not firing the event. So, make sure in the page directive you set AutoEventWireup = false rather than true.  Second, in the page code behind, add the override for the OnInit:

    protected override void OnInit(EventArgs e)
    {
        PreInit += MyApp_PreInit;
        base.OnInit(e);
    }

    void MyApp_PreInit(object sender, EventArgs e)
    {
               MasterPage myMaster=Master as MasterPage;
      Label lbl = (Label)myMaster.FindControl("lblCmdOpt");
        if (lbl.Text == "f123")
        {
        MasterPageFile =  "~//MasterPage.master";
       }
        else
       {
            MasterPageFile = "~//MasterPage2.master";
        }
    }

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0
Mike EghtebasDatabase and Application DeveloperAuthor Commented:
Hi Dan,

I have AutoEventWireup="false"  and also have kept MasterPageFile="~/MasterPage.master"  because removing it doesn't compile:
<%@ Page Title="" Language="C#"  AutoEventWireup="false"    MasterPageFile="~/MasterPage.master" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

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I added breaks at line 3 and 9 to see if the code is firing.

Line 3 is firing when the application first lunched.

But although Response.Redirect("Default2.aspx",false); fires, line 9 never does.

Question: What else I should do for the line 9 fires?

Thank you,

Mike
0
Raghu MutalikdesaiSenior Manager in a leading IT Services companyCommented:
There is an excellent tutorial from Microsoft on this topic. It is fairly elaborate and step by step guide with sample usage. You need to explore <%@ MasterType VirtualPath="" %> in effect.

Here is the link:
http://www.asp.net/web-forms/tutorials/master-pages/specifying-the-master-page-programmatically-cs

MSDN also has an introductory help:
http://msdn.microsoft.com/en-us/library/vstudio/c8y19k6h(v=vs.100).aspx

It is recommended that you use inheritance for your master pages (a hierarchy of master pages).
If you intend to select a master page dynamically, it is recommended that you create a base class from which your master pages derive
0

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Mike EghtebasDatabase and Application DeveloperAuthor Commented:
Thank you.
0
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