C# Signature:

    [DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    static extern uint GetFinalPathNameByHandle(
        IntPtr hFile,
        [MarshalAs(UnmanagedType.LPTStr)] StringBuilder lpszFilePath,
        uint cchFilePath,
        uint dwFlags);

User-Defined Types:

private const uint FILE_NAME_NORMALIZED = 0x0;