Something I've been doing with my ASP.NET applications is creating a shared Page class from which all my Web pages inherit. This allows all the pages to share common functions, settings, and so forth without having to do much work. In ASP.NET 1.1, I used the BasePage class to help control the rendering of the page, but the Master Page in ASP.NET 2.0 eliminated this requirement.

To create a BasePage, you just add a class to your project. In 2.0, this class will go into the App_Code folder. It will inherit from System.Web.UI.Page, so the beginnings of the class will look like the following (C#):

public class BasePage : System.Web.UI.Page
{
}

Once you have the class, you'll need to change your ASP.NET pages to inherit from this class instead of directly from System.Web.UI.Page. Your revised code-behind file for a Web page will resemble the following:

public partial class MyPage : BasePage
{
   protected void Page_Load(object sender, EventArgs e)
   {
   }
}

Now that you have the inheritance set up between the two files, you can add common elements to the BasePage class and make them available to the Web page. For instance, a database-driven Web application might want to automatically open a database connection on each page. You can add this code to the OnInit event of the BasePage class, like so:

public class BasePage : System.Web.UI.Page
{
   public SqlConnection ActiveConnection;
   protected override void OnInit(EventArgs e)
   {
      ActiveConnection = new SqlConnection(...);
      ActiveConnection.Open();
   }
}

The variable named ActiveConnection will now be a live database connection available to any Web page. You'll also want to add the corresponding Close code to the OnUnload event if you open the connection in this manner.

The other thing to remember is that any variables declared as private in the BasePage won't be visible to the Web page, and any variables declared as protected in the BasePage won't be available to the ASPX portion of the Web page, but they will be available to the code-behind part of the ASPX page.