C# Signature:
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public class LOGFONT
{
public int lfHeight;
public int lfWidth;
public int lfEscapement;
public int lfOrientation;
public FontWeight lfWeight;
[MarshalAs(UnmanagedType.U1)]
public bool lfItalic;
[MarshalAs(UnmanagedType.U1)]
public bool lfUnderline;
[MarshalAs(UnmanagedType.U1)]
public bool lfStrikeOut;
public FontCharSet lfCharSet;
public FontPrecision lfOutPrecision;
public FontClipPrecision lfClipPrecision;
public FontQuality lfQuality;
public FontPitchAndFamily lfPitchAndFamily;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
public string lfFaceName;
public override string ToString()
{
StringBuilder sb = new StringBuilder();
sb.Append("LOGFONT\n");
sb.AppendFormat(" lfHeight: {0}\n", lfHeight);
sb.AppendFormat(" lfWidth: {0}\n", lfWidth);
sb.AppendFormat(" lfEscapement: {0}\n", lfEscapement);
sb.AppendFormat(" lfOrientation: {0}\n", lfOrientation);
sb.AppendFormat(" lfWeight: {0}\n", lfWeight);
sb.AppendFormat(" lfItalic: {0}\n", lfItalic);
sb.AppendFormat(" lfUnderline: {0}\n", lfUnderline);
sb.AppendFormat(" lfStrikeOut: {0}\n", lfStrikeOut);
sb.AppendFormat(" lfCharSet: {0}\n", lfCharSet);
sb.AppendFormat(" lfOutPrecision: {0}\n", lfOutPrecision);
sb.AppendFormat(" lfClipPrecision: {0}\n", lfClipPrecision);
sb.AppendFormat(" lfQuality: {0}\n", lfQuality);
sb.AppendFormat(" lfPitchAndFamily: {0}\n", lfPitchAndFamily);
sb.AppendFormat(" lfFaceName: {0}\n", lfFaceName);
return sb.ToString();
}
}
VB .NET Signature:
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
Public Structure LOGFONT
Public lfHeight As Int32
Public lfWidth As Int32
Public lfEscapement As Int32
Public lfOrientation As Int32
Public lfWeight As Int32
Public lfItalic As Byte
Public lfUnderline As Byte
Public lfStrikeOut As Byte
Public lfCharSet As Byte
Public lfOutPrecision As Byte
Public lfClipPrecision As Byte
Public lfQuality As Byte
Public lfPitchAndFamily As Byte
<MarshalAs(UnmanagedType.ByValTStr, SizeConst:=32)> _
Public lfFaceName As String
End Structure
User-Defined Types:
public enum FontWeight : int
{
FW_DONTCARE = 0,
FW_THIN = 100,
FW_EXTRALIGHT = 200,
FW_LIGHT = 300,
FW_NORMAL = 400,
FW_MEDIUM = 500,
FW_SEMIBOLD = 600,
FW_BOLD = 700,
FW_EXTRABOLD = 800,
FW_HEAVY = 900,
}
public enum FontCharSet : byte
{
ANSI_CHARSET = 0,
DEFAULT_CHARSET = 1,
SYMBOL_CHARSET = 2,
SHIFTJIS_CHARSET = 128,
HANGEUL_CHARSET = 129,
HANGUL_CHARSET = 129,
GB2312_CHARSET = 134,
CHINESEBIG5_CHARSET = 136,
OEM_CHARSET = 255,
JOHAB_CHARSET = 130,
HEBREW_CHARSET = 177,
ARABIC_CHARSET = 178,
GREEK_CHARSET = 161,
TURKISH_CHARSET = 162,
VIETNAMESE_CHARSET = 163,
THAI_CHARSET = 222,
EASTEUROPE_CHARSET = 238,
RUSSIAN_CHARSET = 204,
MAC_CHARSET = 77,
BALTIC_CHARSET = 186,
}
public enum FontPrecision : byte
{
OUT_DEFAULT_PRECIS = 0,
OUT_STRING_PRECIS = 1,
OUT_CHARACTER_PRECIS = 2,
OUT_STROKE_PRECIS = 3,
OUT_TT_PRECIS = 4,
OUT_DEVICE_PRECIS = 5,
OUT_RASTER_PRECIS = 6,
OUT_TT_ONLY_PRECIS = 7,
OUT_OUTLINE_PRECIS = 8,
OUT_SCREEN_OUTLINE_PRECIS = 9,
OUT_PS_ONLY_PRECIS = 10,
}
public enum FontClipPrecision : byte
{
CLIP_DEFAULT_PRECIS = 0,
CLIP_CHARACTER_PRECIS = 1,
CLIP_STROKE_PRECIS = 2,
CLIP_MASK = 0xf,
CLIP_LH_ANGLES = (1 << 4),
CLIP_TT_ALWAYS = (2 << 4),
CLIP_DFA_DISABLE = (4 << 4),
CLIP_EMBEDDED = (8 << 4),
}
public enum FontQuality : byte
{
DEFAULT_QUALITY = 0,
DRAFT_QUALITY = 1,
PROOF_QUALITY = 2,
NONANTIALIASED_QUALITY = 3,
ANTIALIASED_QUALITY = 4,
CLEARTYPE_QUALITY = 5,
CLEARTYPE_NATURAL_QUALITY = 6,
}
[Flags]
public enum FontPitchAndFamily : byte
{
DEFAULT_PITCH = 0,
FIXED_PITCH = 1,
VARIABLE_PITCH = 2,
FF_DONTCARE = (0 << 4),
FF_ROMAN = (1 << 4),
FF_SWISS = (2 << 4),
FF_MODERN = (3 << 4),
FF_SCRIPT = (4 << 4),
FF_DECORATIVE = (5 << 4),
}
Notes:
See this MSDN reference: Default Marshaling for Strings
Tips & Tricks:
Please add some!
Sample Code:
// =========================================================================
// EXAMPLE 1 - Filling a Font object with a LOGFONT.
// [in] LayoutDesign.CtlLayout (ActiveX control)
// [out] fontReceived (System.Drawing.Font)
// An ActiveX control returns a handle to a LOGFONT in unmanaged global mem.
IntPtr hHGlobalLOGFONT = (IntPtr)LayoutDesign.CtlLayout.BorderTextLogfont;
// Stake a claim to the memory and get a pointer to it.
IntPtr pLOGFONT = DLLKernel32.GlobalLock(hHGlobalLOGFONT);
// Instantiate a managed logical font struct (as defined above!)
LOGFONT lf = new LOGFONT();
// Copy the LOGFONT data into managed mem.
Marshal.PtrToStructure(pLOGFONT, lf);
// Create the Font object.
Font fontReceived = Font.FromLogFont(lf);
// Release the claim to the global mem.
DLLKernel32.GlobalUnlock(hHGlobalLOGFONT);
// ... Do whatever with the Font object "fontReceived" ...
// =========================================================================
// EXAMPLE 2 - Reversing the process.
// [in] fontReceived (System.Drawing.Font)
// [out] LayoutDesign.CtlLayout (ActiveX control)
// Use the ActiveX's global memory.
IntPtr hHGlobalLOGFONT = (IntPtr)LayoutDesign.CtlLayout.BorderTextLogfont;
// Stake a claim to the memory and get a pointer to it.
IntPtr pLOGFONT = DLLKernel32.GlobalLock(hHGlobalLOGFONT);
// Instantiate a managed logical font struct (as defined above!)
LOGFONT lf = new LOGFONT();
// Load the LOGFONT struct from the managed Font object.
fontReceived.ToLogFont(lf);
// Copy the LOGFONT data into managed mem.
Marshal.StructureToPtr(pLOGFONT, lf, false);
// Release the claim to the global mem.
DLLKernel32.GlobalUnlock(hHGlobalLOGFONT);
// Update the ActiveX control.
(IntPtr)LayoutDesign.CtlLayout.BorderTextLogfont = hHGlobalLOGFONT;
Alternative Managed API:
The .NET Framework class Font, has a method, Font::FromLogfont that takes an Object reference as it's method parameter. You must define a managed LOGFONT class using the same format as the C# signature above. When using the StructLayout attribute on the class definition, you must set the CharSet property to Auto (the default is Ansi, which will not work correctly). The only difficulty encountered is passing the string value (the designated Font Face Name) to the FromLogfont method; apparently, this must have the attribute: [MarshalAs(UnmanagedType::ByValTStr)] enum value for the method to work correctly. Then, when instantiating a new Font in your managed application, you must cast the LOGFONT class (with appropriate member values assigned) to a System::Object for the function to work without generating a runtime exception.
