Trace.WriteLine doesn't work

micdenny

Is it normal that Trace.WriteLine doesn't work in anyway, when I run the code with just a few line of Trace.WriteLine, nothing happen even if I add any kind of TraceListener, and what is weird is that the IL is completly empty.

void Main()
{
Trace.Listeners.Clear();
Trace.Listeners.Add(new ConsoleTraceListener());

Trace.WriteLine("adads");
Trace.WriteLine("adads");
Trace.WriteLine("adads");
}

IL

IL_0001: call System.Diagnostics.Trace.get_Listeners
IL_0006: callvirt System.Diagnostics.TraceListenerCollection.Clear
IL_000B: nop
IL_000C: call System.Diagnostics.Trace.get_Listeners
IL_0011: newobj System.Diagnostics.ConsoleTraceListener..ctor
IL_0016: callvirt System.Diagnostics.TraceListenerCollection.Add

As you can see the IL stops just after the adding of the listener.

If I run only some Trace

void Main()
{
Trace.WriteLine("adads");
Trace.WriteLine("adads");
Trace.WriteLine("adads");
}

No IL at all!

It seems like linqpad doesn't like Trace stuff, and removes them all before running the code.

I'm running the version v4.51.03

Thanks for any suggestions.

sgmoore

By default TRACE isn't defined and hence the Trace.WriteLine's are not compiled.

Try

#define TRACE

void Main()
{
Trace.WriteLine("adads");
Trace.WriteLine("adads");
Trace.WriteLine("adads");
}

and LinqPad should output the lines to the result panel.

micdenny

Oh yes, now works! I didn't thought to try define the symbol, because by default in release is defined.

Thanks again!

JoeAlbahari

To save typing, and to get the benefit of LINQPad's output formatting, you can instead call DumpTrace():

"asdf".DumpTrace()

As with Trace.WriteLine, output is suppressed unless you define the TRACE symbol.