pinvoke.net: gdi32.getoutlinetextmetrics

C# Signature:

[DllImport("gdi32.dll")]
static extern uint GetOutlineTextMetrics(IntPtr hdc, uint cbData, IntPtr ptrZero);

User-Defined Types:

Notes:

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

First call returns needed buffer size the second fills buffer by actual data.

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.)

Sample Code:

private static void GetOutlineMetrics(IntPtr hdc)
{
    uint cbBuffer = GetOutlineTextMetrics(hdc, 0, IntPtr.Zero);
    if (cbBuffer == 0)
        return;
    IntPtr buffer = Marshal.AllocHGlobal((int)cbBuffer);
      try
    {
        if (GetOutlineTextMetrics(hdc, cbBuffer, buffer) != 0)
        {
            OUTLINETEXTMETRIC otm = new OUTLINETEXTMETRIC();
            otm = (OUTLINETEXTMETRIC)Marshal.PtrToStructure(buffer, typeof(OUTLINETEXTMETRIC));
            string otmpFamilyName = Marshal.PtrToStringAnsi(new IntPtr((int)buffer + otm.otmpFamilyName));
            string otmpFaceName = Marshal.PtrToStringAnsi(new IntPtr((int)buffer + otm.otmpFaceName));;
            string otmpStyleName = Marshal.PtrToStringAnsi(new IntPtr((int)buffer + otm.otmpStyleName));;
            string otmpFullName = Marshal.PtrToStringAnsi(new IntPtr((int)buffer + otm.otmpFullName));;
        }
    }
    finally
    {
        Marshal.FreeHGlobal(buffer);
    }
}

Alternative Managed API:

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Documentation

GetOutlineTextMetrics on MSDN