How to dynamically change master page?

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Hi,
How can I dynamically change the MasterPager of a web page?

 

[Mark Rae]

How can I dynamically change the MasterPager of a web page?

private void Page_PreInit(object sender, EventArgs e)
{
this.MasterPageFile = "MyNewPasterPage.master" // amend as
appropriate
}

 

[clintonG]

The MasterPage does not support the Page_PreInit so it has to be used in
each content page or a base class must be used which all content pages
inherit from.

<%= Clinton Gallagher
NET csgallagher AT metromilwaukee.com
URL http://www.metromilwaukee.com/clintongallagher/

 

[Mark Rae]

The MasterPage does not support the Page_PreInit

I didn't say it did...

so it has to be used in each content page or a base class must be used
which all content pages inherit from.

Correct.

 

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Thanks,
But if I wish when an user press a button on web page, it will do the change
of mastPage.
How can I do that?

 

[Mark Rae]

Thanks,
But if I wish when an user press a button on web page, it will do the
change of mastPage.
How can I do that?

Do you want the selected MasterPage to be for the whole site (for the
current user), or just for the current page?

 

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For just one page, and change it for a while.

Do you want the selected MasterPage to be for the whole site (for the
current user), or just for the current page?

 

[Mark Rae]

For just one page, and change it for a while.

OK, then.

The *only* place that a content page can set its MasterPage is in its
Page_PreInit method, so you're going to have to do the following:

For each content page for which you want to enable dynamic MasterPages,
you'll need to set up a Session variable, which you'll need to initialise on
the Session_Start method in global.asax.

1) E.g. let's say you have a page called MyPage.aspx - in Session_Start,
you'll need to do the following:

Session["MyPage_Master"] = "~/master/Master1.master";

2) In the Page_PreInit of MyPage.aspx, you'll need to do the following:

private void Page_PreInit(object sender, EventArgs e)
{
this.MasterPageFile = Session["MyPage_Master"].ToString();
}

3) To change the MasterPage, you'll simply need to create an <asp:Button> or
any other webcontrol which can cause a postback, set the
Session["MyPage_Master"] session variable to the new MasterPage, then
Response.Redirect the page back to itself.

Thereafter, whenever MyPage.aspx is called, it will set its MasterPage to
whatever value is in the Session["MyPage_Master"] session variable.

Sounds a bit convoluted, but it's fairly straightforward once you get your
head round it... Good luck!

 

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Thanks,
Your answer is great, but I have a question about your answer.
Why we need to Response.Redirect the page back to itself after change the
Session variable of MasgerPage.
I have test if it didn't Response.Redirect the page back to itself, just
let the page postback, the MasterPage will not change at the fist postback,
I must postbak twice to make the change.

Why?

For just one page, and change it for a while.

OK, then.

The *only* place that a content page can set its MasterPage is in its
Page_PreInit method, so you're going to have to do the following:

For each content page for which you want to enable dynamic MasterPages,
you'll need to set up a Session variable, which you'll need to initialise
on the Session_Start method in global.asax.

1) E.g. let's say you have a page called MyPage.aspx - in Session_Start,
you'll need to do the following:

Session["MyPage_Master"] = "~/master/Master1.master";

2) In the Page_PreInit of MyPage.aspx, you'll need to do the following:

private void Page_PreInit(object sender, EventArgs e)
{
this.MasterPageFile = Session["MyPage_Master"].ToString();
}

3) To change the MasterPage, you'll simply need to create an <asp:Button>
or any other webcontrol which can cause a postback, set the
Session["MyPage_Master"] session variable to the new MasterPage, then
Response.Redirect the page back to itself.

Thereafter, whenever MyPage.aspx is called, it will set its MasterPage to
whatever value is in the Session["MyPage_Master"] session variable.

Sounds a bit convoluted, but it's fairly straightforward once you get your
head round it... Good luck!

 

[Mark Rae]

Your answer is great, but I have a question about your answer.
Why we need to Response.Redirect the page back to itself after change the
Session variable of MasgerPage.
I have test if it didn't Response.Redirect the page back to itself, just
let the page postback, the MasterPage will not change at the fist
postback, I must postbak twice to make the change.

Why?

Because the MasterPage can *only* be set in a content page's Page_PreInit
method.