The first tool I’ve launched during my first tests with Metro applications was DebugView from SysInternals.
This utility is notified when your application is calling the Win32
OutputDebugString function outside of a debugger (see this CodeProject article about a simple implementation based on the Win32 SDK).
IN C#, Debug.WriteLine by default calls
OutputDebugString behind the scene, so it is very handy to get traces outside of a debugger control. Unfortunately, the current version was not catching the
OutputDebugString calls from Metro applications.
But this time is over thanks to Mark Russinovich!
Download the last version and have fun with Windows 8 Consumer preview.
I hope this helps.