when i open a handle to console screenbuffer (CONOUT$) with FILE_FLAG_OVERLAPPED - its ok, handle is created.

When i call WriteFile in synchronous mode, it return 1 and GLA = ERROR_SUCCESS, and data is written.

when i call WriteFile with asynchronous mode, it return 0, GLA = ERROR_INVALID_ACCESS, and data is also written!

when i call WriteFileEx, it return 0, GLA = ERROR_INVALID_HANDLE, data isnt written, callback isnt executed.

why it does happen?
why it works only in synchronous mode? why in asynchronous mode it returned ERROR_INVALID_ACCESS, and data was written?
why Ex function doesnt work? microsoft dont document this behavior, please help

CreateFile (http://msdn.microsoft.com/en-us/library/aa363858(v=VS.85).aspx) says it ignores flags for CONxxx so it looks like it's forced to synchronous.

indeed it is ignbored, i must have missed that.

but look at WriteFileEx:
http://msdn.microsoft.com/en-us/library/aa365748%28VS.85%29.aspx




clearly it allow console handle, so why it fail?