Since otmpFamilyName, otmpFaceName, otmpStyleName, otmpFullName are actually offsets into the structure from the beginning of the structure you need double call GetOutlineTextMetrics.

Warning

The OUTLINETEXTMETRIC structure includes a TEXTMETRIC structure which includes some TCHAR fields. A TCHAR can compile to a 16 bit character or a 8 bit character (depending on whether UNICODE is defined). The C# version of the TEXTMETRIC structure on PInvoke.net assumes that the TCHAR is a 16 bit character and when you retrieve a TEXTMETRIC structure with GetTextMetrics you do get a TEXTMETRIC structure with 16 bit characters. However, when you retrive an OUTLINETEXTMETRIC structure with GetOutlineTextMetrics the included TEXTMETRIC structure appears to have 8 bit characters. (These observations were with Windows XP and might not hold true for other operating systems or all fonts.)

uint cbBuffer = GetOutlineTextMetrics(hdc, 0, IntPtr.Zero);

if (GetOutlineTextMetrics(hdc, cbBuffer, buffer) != 0)

OUTLINETEXTMETRIC otm = new OUTLINETEXTMETRIC();

otm = (OUTLINETEXTMETRIC)Marshal.PtrToStructure(buffer, typeof(OUTLINETEXTMETRIC));

Documentation

[GetOutlineTextMetrics] on MSDN

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