Data persistence and updates in ASP.NET Web Forms

I'm currently working on a web app/game using C# and ASP.NET(3.5). However, I'm running into a problem of variables used in the main page being reset to null wheneve开发者_StackOverflow中文版r I click a button on the web form. I'm wondering if there was a way to allow to variables to persist for the life cycle of the entire application, as well as for the variables to be accessed from wherever/whenever.

Another issue I'm having at the moment is that I can't seem to find a way to update the properties of controls, like text or colour, without having to refresh the page. Is there a way to update these properties "silently" without forcing the user to go through the whole page refresh cycle?

Thanks

1. Use Session collection to persist for a particular user. Alternatively use static variables to keep their values for the lifetime of the application domain (for all site users until the web server restarts or crashes).

2. To update page portions "silently" wrap them into UpdatePanels (Microsoft AJAX library thing) or use JavaScript (you can use some JS library like jQuery to make it easier and handle the cross-browser compatibility for you) to manipulale the structure of your document on-the-fly.

It really depends on the purpose of the variables, and their scope.

For variables that are different for each visitor, you want to place those variable into session.

For variables that are global to your whole app, and are the same for every visitor, then you can either use static variables, or put them into web.config as Application Settings

Changing text/color on the client, this sounds like you might need to make use of some javascript. JQuery is a javascript library that makes a lot of those type of manipulations easier.

You might have ViewState disabled at Page Level (or application level).

Usually ASP.NET stores the state of each control within the current page in the Viewstate Object to preserve their status over reloads. Have a look at the EnableViewState object in your code (Front End) or dig into the web.config.

If you also want data to persist at page level, use the Session object and work around the timeout property to find a suitable value that will work for you and your users. SlidingExpirationg could also be useful. If you are going to use this solution you might also ask yourself some questions. Is your application using 1 single server or is likely to be deployed to a server farm? If so, consider using SQL Session State instead of InProc as it will provide a more consistent "centric" place to stored the session data consumed by different servers.

Regarding updating controls without a page refresh you are looking for something called Ajax. Microsoft has release ASP.NET Ajax Toolkit, have a look at it, especially the asp:UpdatePanel which will let you "partial update" pieces of the page without reload everything else.

It's the easiest, straight forward, way to update controls properties without much effort.

Additionally, to update the client side objects without a postback to the server, you'll need to use javascript. jQuery will probably be your best bet.