ASP.NET Trace - Custom HttpModule

Question

We have developed our custom HttpModule.
Now I want to add ability to trace it, and see the trace results in standart ASP.NET tracing page (or trace.axd). I try to use System.Diagnostics.Trace.Write("FILTER TEST"); to write trace information. This works everywhere except of HttpModule. I added a trace listener in web.config, but it only shows traces that were written during the page lifecycle. How i can see the trace information that i write in HttpModule and how I can add this information to ASP.NET trace page?

<trace>
  <listeners>
    <add name="WebPageTraceListener"
         type="System.Web.WebPageTraceListener, System.Web, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
  </listeners>
</trace>

score 0 · Answer 1 · answered Jan 15 '13 at 18:11

0

Have you tried to use System.Web.IisTraceListener? See: http://www.iis.net/learn/develop/runtime-extensibility/how-to-add-tracing-to-iis-managed-modules

answered Jan 15 '13 at 18:11

Al3x3

463
3
9

score 0 · Answer 2 · answered Jul 25 '13 at 08:11

I usually use TraceSource and it works fine even within custom HttpModule.

All you need is :

Declare a source (you can use as many sources as you want in your code, it depends of what you want for the granularity over your tracing) - (more information on TraceSource here):
```
public class MyModule : IHttpModule
{
    public static readonly TraceSource MyTraceSource = new TraceSource("MySource", SourceLevels.Off);
(...)
}
```
Within your code, use TraceEvent whenever you need your source to dump something in the trace (more information on the traceEvent method here) :
```
MyModule.MyTraceSource.TraceEvent(TraceEventType.Information, 0, "Message that'll be dumped in the trace");
```

In your config file you can enable/disable only the tracesource you want at the level you want (information, warning, error, ...)

<system.diagnostics>

    <trace autoflush="true"/>

    <sharedListeners>
        <add name="myListener" initializeData="..." type="..."/>
    </sharedListeners>

    <sources>
        <source name="MySource" switchName="VerboseSwitch" >
            <listeners>
                <clear/>
                <add name="myListener"/>
            </listeners>
        </source>
        <source name="OtherSource" switchName="OffSwitch" >
            <listeners>
                <clear/>
                <add name="myListener"/>
            </listeners>
        </source>
    </sources>

    <switches>
        <clear/>
        <add name="OffSwitch" value="Off"/>
        <add name="VerboseSwitch" value="Verbose"/>
        <add name="InformationSwitch" value="Information"/>
        <add name="WarningSwitch" value="Warning"/>
        <add name="ErrorSwitch" value="Error"/>
    </switches>

</system.diagnostics>

Here you can find a really great article on the trace subject : http://www.codeproject.com/Articles/149251/Debugging-Tracing-and-Instrumentation-in-NET-and-A

Hope this helps !

ASP.NET Trace - Custom HttpModule

2 Answers2