I'm making an ASP.NET application that performs some globalization in the Render event of the Master Page. Basically my code uses regular expressions to look for placeholders (text patterns, not actual PlaceHolder controls) in the markup and replaces them with the corresponding translations found in an XML file.
This works as intended when the page is loaded normally, but on a partial postback the Render event does not seem to trigger at all for the Master Page, leaving the rendered page full of placeholders. The event does trigger for the current Page however, but I don't want to alter the output HTML separately in every single page's Render event.
The ContentPlaceHolder (containing the current Page) of the Master Page is located inside an UpdatePanel, and I assume this has something to do with what is happening. I still don't understand why the event is not triggered, however.
Is there a way to force the Master Page Render event to trigger on partial postback, or should I consider a different solution?
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Why we set master page in Page_Init event. We have other events in page.
For me one reason could be that master page does not have Pre_Init and other could be that Init of Page occurs before master page Init. Correct me if I'm wrong.
Master page is a UserControl. During Page.Init event, all the controls on the page are initialized(Control.Init is called). That's why the master page needs to be applied in Page.PreInit
Masterpage doesn't have PreInit method.
Master pages inherits:**System.Web.UI.MasterPage** and as per the design of this MasterPage class no such PreInit event is defined for this class.
Master pages are derived from Control class as seen in below hierarchy:
System.Object
System.Web.UI.Control
System.Web.UI.TemplateControl
System.Web.UI.UserControl
System.Web.UI.MasterPage
Therefore as can be guessed now, Master pages behave and in essence are treated like a control and have events similar to other asp.net server control
Because all things that 'dynamically' modify page controls have to occur there. This is where the page is rebuilt (form objects) with out request. Then things like page_load occur, after all objects are made.
Winforms analogy - if you are familiar with that - page_init is analogous to the InitializeComponent in the New (NOT REALLY SAME - just analogy please).
Only due to the nature of the web (at least round-tripping to the server), it can't possibly work like winforms (or WPF or even a SPA web app with a js/DOM UI and webapi backend) so has to rebuild the form's objects EVERY request.
Why does only the PAGE have page_init and not master page? Well as prateek says, but in addition, the rebuild of the page has to be control from just one spot. There is just one request. Controls can init, too as the page init process calls them in turn.
You have asked a question with a complicated answer.
Here is a good chart of what's going on...
http://www.codeproject.com/KB/aspnet/ASPDOTNETPageLifecycle.aspx
(source: codeproject.com)
Note how the postback data is loaded into the controls BEFORE the page_load, too - this is why it's too late to do anything big in the page load. You can't possibility get anything back from the user that was changed there (unless you go right to the postback data). The picture shows how ASP tries to 'fake' an event - driven UI on a client/server web architecture (e.g., 'event related logic' calls your 'events'). There is no such thing in client/server asp UI!
As a master page is the default screen throught the application ,it should be initialized first before the child pages.In order to get initalized earlier it is done in pre_init where the master page is loaded.later in Init() all the child pages are loaded regarding to that master page.
During the ASP.NET page life cycle, the initialization is also included on the master page. This is where the design and all the controls that are on the master page will be available before the page is loaded, which will be the "Load" phase of the page life cycle. If the master page is not initialize, you would get a page with no design, except the information on the page.
"During page initialization, controls on the page are available and each control's UniqueID property is set. A master page and themes are also applied to the page if applicable. If the current request is a postback, the postback data has not yet been loaded and control property values have not been restored to the values from view state."
https://msdn.microsoft.com/en-us/library/ms178472.aspx
I have Implemented the Globalization in my Page. I have specified the Flags for changing one language to another.
When I click the Flag I am setting the Application["LangId"]="1"; Now the content of the master page is refreshing but the content of the child page does not refresh. Because I have called setting the Language in every child Page load. According to the terminology Child page load fires first and after Master page load and the Click event. If I call the Language setting method in click event I will get the refreshed content.
My question is how we can call the child page method in master page button click event.
You can define a property in your master.
public flag{get;set;}
And load it in page load. Then you can access that from child pages like this:
var flag=((MasterPage)Master).flag;
If you load your child pages this way, they will be refreshed whenever that property changes on MasterPage (if page is refreshed of course)
Hi I am working on a website in which i need to access certain content pages from a treeview placed in a master page. When I am using Response.Redirect on the SelectedNodeChanged event of the tree view the entire page postbacks instead of the UpdatePanel(of the content page).Am i missing something or is this the expected behaviour.Also is there a work around for this?Please help
I believe Response.Redirect will always refresh the whole page, this is an Update Panel not an iframe. Why not place an iframe into the page, into an Update Panel. OnClick of the tree, set the src of iframe to what you want, then call UpdatePanel.Update()...
Got a very frustrating problem that I'm trying to solve regarding C#.NET's way of handling dynamically added usercontrols.
The basic rundown of my page setup is that I have an ASPX page which has a Master Page. The Master Page has some content placeholders. On the codebehind in the ASPX page, I call the Master.FindControl method to find the content placeholders, and then use the LoadControl method to load a UserControl into the placeholder.
On the UserControl, I have a series of textboxes, and a submit button. In this implementation, when I click on the submit button, and put a breakpoint into the OnClick event, I find that the OnClick event is never called.
However, if, instead of using this approach, I remove the Master Page, and add the content placeholders directly on the ASPX page, then use Placeholder.Controls.Add to add the UserControl instead of Master.FindControl, the button works perfectly.
Does anyone have any suggestions as to how I can resolve this without removing the Master Page?
From what I've already read this appears to be impossible, but I wanted to see if anyone out there has a secret trick up their sleeve or at least a definitive "no".
Supposedly a master page is really just a control for a content page to use, not actually the "master" of a content page. If I wanted to go from one content page, to another content page with the same master page, I would just say
Response.Redirect("PageB.aspx");
But this would immediately cause a postback, flickering the page, which is the crappy pre-ajax way of doing things.
In this current project, I'm trying to see if I could figure out how to change the current content page of a ContentPlaceHolder in the master page asynchronously, when a button is clicked on the master page.
Is this possible, if so how?
I don't know if you can between pages (.aspx) but it can definitely be done using UserControls.
ASP.Net pages each have their own URL so what you're trying to do is to go from one URL to another without any postback, that's just not how it's supposed to work.
Using user controls (.ascx):
Create a page that uses the MasterPage and use something like this in the content
<ajax:UpdatePanel ...>
<ContentTemplate>
<asp:PlaceHolder ...>
</ContentTemplate>
</ajax:UpdatePanel>
Search for UpdatePanel and tweak its settings to do what you want, then learn how to swap user controls in a placeholder.
No, you cannot because a master page is actually a control rendered on a particular aspx page, rather than actually containing the aspx page as it deceptively appears to be programmatically and in design view.
More Info:
You could however use a variety of other controls to simulate this effect. The asp:MultiView control is one example, each "page" could be made in a single view and placed in an update panel, thus allowing it to be switched asynchronously. Alternatively you could define each page in a separate user control and put those in an update panel, asynchronously switching the visible property on those controls as needed.
There are really a lot of different ways to achieve an effect similar to changing the master page's content placeholder.