We faced the similar problem, All you need to do is just register the handler in the constructor. :)

public class FactsheetBase : System.Web.UI.Page { public FactsheetBase() { this.Load += new EventHandler(this.Page_Load); } public MyPageData Data { get; set; } protected void Page_Load(object sender, EventArgs e) { // get data that's common to all implementors of FactsheetBase  // and store the values in FactsheetBase's properties  this.Data = ExtractPageData(Request.QueryString["data"]); } }

Another approach would be to override OnLoad() which is less preferred.

public class FactsheetBase : System.Web.UI.Page { public FactsheetBase() { } public MyPageData Data { get; set; } protected override void OnLoad(EventArgs e) { //your code // get data that's common to all implementors of FactsheetBase  // and store the values in FactsheetBase's properties  this.Data = ExtractPageData(Request.QueryString["data"]); base.OnLoad(e); } }