| System.Web (system.web.dll) | sealed class |
The TraceContext class allows you display trace
messages that can help you debug ASP.NET applications. To enable
tracing for a specific page, insert the page directive
Trace="True" in the ASPX file or set the
IsEnabled property of the
TraceContext class in your code-behind module.
The TraceContext class provides two methods:
Write( ) and Warn( ). Both
display a message in the current page's trace log,
but Warn( ) uses red lettering that is meant to
indicate exception information. You can invoke the Write(
) or Warn( ) method with a category
string and message string. Often, the category string indicates the
position in the code ("In
FunctionA"), while the message string indicates
specific information ("Exception while opening
database"). Additionally, an overloaded version of
Write( ) and Warn( ) allows you
supply an exception object that ASP.NET will use to extract the
appropriate information. Even if you don't use the
Write( ) and Warn( ) methods,
ASP.NET automatically inserts trace log entries to indicate standard
events, and appends a great deal of information after the list of
trace message, including performance data, tree-structure
information, and state management content.
The TraceContext class is provided as the built-in
Trace object. You can use the
web.config file to set additional tracing
options like the default TraceMode, and enable
application-wide tracing. Application-wide tracing can be displayed
on the page or cached exclusively in memory.
public sealed class TraceContext {
// Public Constructors
public
TraceContext (HttpContext
context );
// Public Instance Properties
public bool
IsEnabled {set; get; }
public TraceMode
TraceMode {set; get; }
// Public Instance Methods
public void
Warn (string
message );
public void
Warn (string
category , string
message );
public void
Warn (string
category , string
message , Exception
errorInfo );
public void
Write (string
message );
public void
Write (string
category , string
message );
public void
Write (string
category , string
message , Exception
errorInfo );
}
Returned By
HttpContext.Trace,
System.Web.UI.Page.Trace,
System.Web.UI.UserControl.Trace