We can enable ASP.NET tracing on a page-by-page basis by adding "Trace=true" to the Page directive in any ASP.NET page.

Listing 1

<%@ Page Language="C#" Trace="true" TraceMode = "SortByCategory" 
    Inherits  = "System.Web.UI.Page" CodeFile="Default.aspx.cs" %>

We can also add the TraceMode attribute that sets SortByCategory or the default, SortByTime. SortByTime option is used to see the methods that take up the most CPU time in application. We can enable tracing programmatically using the Trace.IsEnabled property.