how do you control the level of a trace listener in the config file

Question

I'm trying to learn the built-in features of tracing. I can't figure out how to use the config to set the level (information, warn, error) that gets written to my listen.

I have the default app.config with it . In my code, I use Trace.TraceInformation() and Trace.TraceError.

All of the messages are written to my text file. I want to be able to change something in the app.config to make it record Info messages or just error messages.

Module1.vb

Sub Main(ByVal args() As String)     Dim index As Integer = 0     For Each arg As String In args         Trace.TraceInformation(String.Format("Sub Main(): arg({1}) = {0}", arg, index))         Trace.Flush()          If arg.Split("=").Count = 2 Then             If String.Compare(arg.Split("=")(0), "mode", True) = 0 Then _Mode = arg.Split("=")(1)         End If          index += 1     Next End Sub 

app.config

    <sources>         <!-- This section defines the logging configuration for My.Application.Log -->         <source name="DefaultSource">             <listeners>                 <add name="FileLog"/>                 <!-- Uncomment the below section to write to the Application Event Log -->                 <!--<add name="EventLog"/>-->             </listeners>         </source>     </sources>     <switches>         <add name="DefaultSwitch" value="1" />      </switches>     <sharedListeners>         <add name="FileLog"              type="Microsoft.VisualBasic.Logging.FileLogTraceListener, Microsoft.VisualBasic, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"              initializeData="FileLogWriter"/>         <!-- Uncomment the below section and replace APPLICATION_NAME with the name of your application to write to the Application Event Log -->         <!--<add name="EventLog" type="System.Diagnostics.EventLogTraceListener" initializeData="HealthSurvey Console"/> -->     </sharedListeners>  </system.diagnostics> 

Answer 1

I'm not a fan of answering your own questions, but I also don't like leaving questions without marking something as the answer. This is especially true when I found what I was looking for.

This link had the info I needed. I will summarize because it is pretty long. In the config, you add a listener. The key that I needed was using the <filter> for the listener. With it, I can deploy my application and then change the config to control the text written to the file. I could add another listener that had a different filter like maybe the eventlog.

Anyway, the key was <filter>. The attribute initializeData is set to the text from System.Diagnostics.SourceLevels enum.

• Information allows Information, Warning, and Error
• Warning allows Warning and Error
• Error allows Error only

app.config

<system.diagnostics>   <trace autoflush="false" indentsize="1">     <listeners>       <add name="textListener"            type="System.Diagnostics.TextWriterTraceListener"            traceOutputOptions="None"            initializeData="C:\Projects\TraceLogOutput.log">         <filter             type="System.Diagnostics.EventTypeFilter"            initializeData="Information"/>       </add>     <remove name="Default" />   </listeners> </trace> 

module1.vb

Sub Main(ByVal args() As String)      ' initializeData = Information only     Trace.TraceInformation("Some Information message")     Trace.Flush()      ' initializeData = Information or Warning     Trace.TraceWarning("Some Warning message")     Trace.Flush()      ' initializeData = Information, Warning or Error     Trace.TraceError("Some Error message")     Trace.Flush()  End Sub