What is the point of HttpApplication.CompleteRequest()? - asp.net

Question

I have made a simple web form with some static HTML on the design view, and on the code behind I put on two methods: Page_Load and Page_PreRender as follows:
public partial class SamplePage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Response.ClearContent();
Response.ClearHeaders();
Response.StatusCode = (int)HttpStatusCode.NotFound;
Respons.Write("Not Found");
Context.ApplicationInstance.CompleteRequest();
}
protected void Page_PreRender(object sender, EventArgs e) // Why does this event get called? Should not the CompleteReqeust()
{ // cause the page to jump directly to the end of events pipeline?
throw new NotImplementedException();
}
}
Moreover, I have read so many Q&As about Response.End() being "ugly", "dangerous", etc, even from MSDN website. But it puzzles me a lot, why if so the Response.Redirect(string) still uses Response.End() internally?

Answer 1

Overriding IHttpHandler's ProcessRequest(HttpContext) in the Page is enough to do the trick.
public partial class SamplePage : System.Web.UI.Page
{
public override void ProcessRequest(System.Web.HttpContext context)
{
if (conditionTrue)
{
context.Response.StatusCode = 404;
context.ApplicationInstance.CompleteRequest();
}
else
{
base.ProcessRequest(context);
}
}
protected void Page_Load(object sender, EventArgs e) // This is not called also :P
{
}
protected void Page_PreRender(object sender, EventArgs e) // Not called now :)
{
throw new NotImplementedException();
}
}