You want your application to output trace information to the event log and, at the same time, control what level of information is output.
Create your own trace listener that inherits from the
TraceListener class and overrides the
WriteLine methods to
their output to
the event log. A sample trace listener we’ve written
to demonstrate this solution is shown in Example 10-20
(VB) and Example 10-21 (C#).
Next, modify your
web.config file to add the
TraceSwitch, as shown in Example 10-22.
In the classes you want to output trace information, create a
TraceSwitch object using the name of the
TraceSwitch you added to the web.config file, and then use the
Trace class to output the required
messages, as we demonstrate in our class in Example 10-23 (VB) and Example 10-24 (C#).
The technique we advocate for writing trace information to the event
log involves creating your own custom trace listener that overrides
and directs their output to the event log. We also find it useful to
control the level of messages that are output to the event log, such
as outputting only error messages or outputting error and warning
messages. Controlling the level of messages that are output involves
the use of switches (more about this in a minute).
As discussed in Recipe 10.5, you can add additional listeners to ...