Listeners : 6

 We flush the listeners buffer that just clears all the messages and put them where they need to be the last step is to display that message on the page and then do a cleanup that just ties up all the loose ends of the listeners now access the application first welcome back of the web.config make sure that I have my switches set and I do Boolean switch is set to once.

 It's true and the multi-switch is set to four which is going to be verbose just means of this good output all the messages I'll go and run the application and I'll click on the trace which is an trace listeners like there scroll down a bit here and you can see that we have some output text based on the settings of the switches and the information that we generated within the page obviously probably not going to add this kind of information to the page but you could but you could also do other things conditionally.

Based on the switch settings that you specify within web.config elbow back over to Visual Studio else like the tracing project will go ahead and stop the application to refresh the list of files and we can see that we have a new file here called trace log.txt I can open that up and you can see that we have that output which was sent to the text writer listener similarly you can go into the Windows event log and see that there are messages that are stored there because we used an event log listener right let's go back over the web.config.

And let's set the Boolean switch to zero and let's set this switch to one and I'll go ahead and run the application again will select default.aspx and that's the start of page and click on the link and I can see the results are different in the page on the back of the Visual Studio it tells me the trace log.txt changed Saul reload that and take a look at it and now has different contents based on the conditions of the switches that are set within web.config that even though most of the messages were written using only the pages trace.write method and didn't use the system.diagnostics.trace object all the messages were routed to the listeners because the web.config file set.

The right to diagnostics trace option to true there's another trace listener that is a part of system.diagnostics the system.Web namespace includes a trace listener drive type called webpage trace listener what it does is it serves as a counterpart to the right to diagnostics trace what this means is that the webpage trace listener what you go the other way and monitor components that use the system.diagnostics classes for tracing and captures the system.diagnostics.trace messages in ASP.net page traces when you add an instance of the webpage trace listener is added to the trace listeners collection and messages written to the.net diagnostics trace.