Question

Thread.CurrentThread.CurrentCulture.NumberFormat.CurrencySymbol = "$";
decimal value = 500;
Trace.TraceInformation("{0:C}", value);
Trace.TraceInformation(string.Format("{0:C}", value));

produces the following output:

Information: 0 : ¤500.00
Information: 0 : 500,00$

That means it either performs formatting on a different thread or ignores Thread.CurrentThread.CurrentCulture (probably replacing it with invariant one). WHY?? MSDN keeps silence.

Answer 1

Correct, Trace output explicitly uses CultureInfo.InvariantCulture. Decompiled source for TraceListener.TraceEvent has it this way:

this.WriteLine(string.Format(CultureInfo.InvariantCulture, format, args));

You already provided a workaround: format for any culture you want at the call site.