设置自动刷新.Net跟踪侦听器的日志记录级别

Question

In a .Net 4.0 web-service I am using trace autoflush to write to a log file.

By adding the following in the web.config:

<trace autoflush="true" >
  <listeners>
    <add name="TextWriter"
         type="System.Diagnostics.TextWriterTraceListener" 
         initializeData="trace.log" >
    </add>
  </listeners>
</trace>

Am trying to find a way to log only Trace.TraceError("error info") and exclude Trace.TraceInformation("some verbose debugging stuff") without altering my code and just changing the web.config?

The information I have found on MSDN shows how this can be done by adding code that calls Trace.Flush() and adding sources, switches and sharedlisteners, however I would like to continue using auto-flush and not alter the code.

Many thanks in advance :)

Answer 1

Old answer:

This appears to be impossible. Trace auto-flush does not have the capacity to have it's level set in the web.config.

Update:

The listener may have a filter applied as follows

<configuration>
<system.diagnostics>
    <trace autoflush="true"  >
        <listeners>
            <add name="TextWriter"
                     type="System.Diagnostics.TextWriterTraceListener"
                     initializeData="trace4.log" >
                <filter type="System.Diagnostics.EventTypeFilter" initializeData="Warning" />
            </add>
        </listeners>
    </trace>
</system.diagnostics>

Note that the initializeData is a string and may take the values of Warning or Error. This filters the trace output accordingly.

Many thanks to Josip for following up on this question.

Answer 2

Maybe you can use " switchValue " for this purpose like this:

<system.diagnostics>
    <trace autoflush="true">
    </trace>
    <sources>
        <source name="SCInterface" switchType="System.Diagnostics.SourceSwitch" **switchValue**="All">
            <listeners>
                <remove name="default"/>
                <add name="HSInterface"
                type="XYZ.Diagnostics.CyclicTextTraceListener, XYZ.Base3x"
                initializeData="D:\Trace\HSR.HSInterface.Trace.log, Size, 10, 5"
                traceOutputOptions="DateTime,ThreadId,Callstack" />
            </listeners>
        </source>
    </sources>
</system.diagnostics>

For switch value you would put Warning or Error...