如何获得字体可用字号

function EnumFontsSize(var LogFont: TLogFont; var TextMetric: TTextMetric;
 FontType: Integer; Data: Pointer): Integer; stdcall;
begin
 TStrings( Data ).Add(IntToStr( LogFont.lfHeight) );
 Result := 1;
end;
procedure GetFontSizeList( FontName : String; List : TStrings );
//FontName,是字体名；
//这种字体的所有可用尺寸将被填在List中。
var
 DC: HDC;
begin
 List.Clear;
 DC := GetDC(0);
EnumFonts(DC, PChar(FontName), @EnumFontsSize, Pointer(List));
 ReleaseDC(0, DC);
end;

var
 Form1: TForm1;
  VRES:Integer;
const
 MaxStdSizes=16;
function EnumFontFamiliesProc(var LogFont: TLogFont; var TextMetric: TTextMetric;
 FontType: Integer; Data:Pointer): Integer; {$IFDEF WIN32} stdcall; {$ELSE} export; {$ENDIF}
 procedure AddToList(const aValue:String);
 var
   j:Integer;
   c:Boolean;
 begin
   j:=0;
   c:=False;
   with TListBox(Data) do
     begin
       while (j<Items.Count) and not c do
         if StrToInt(aValue)>=StrToInt(Items[j]) then Inc(j) else c:=True;
       Items.Insert(j, aValue);
     end;
 end;
var
 i:Integer;
 c:String;
const
 csizes:array[0..MaxStdSizes-1] of Integer=(8,9,10,11,12,14,16,18,20,22,24,26,28,36,48,72);
begin
 result:=0;
 with TListBox(Data) do
   begin
     if (FontType and TRUETYPE_FONTTYPE=TRUETYPE_FONTTYPE) or (FontType in [0,2]) then
       begin
         For i:=0 to (MaxStdSizes-1) do Items.Add(IntToStr(Csizes[i]));
         result:=0
       end;
     if (FontType and RASTER_FONTTYPE=RASTER_FONTTYPE)
     {or (FontType and DEVICE_FONTTYPE=DEVICE_FONTTYPE)} then
       with TextMetric do
         begin
           c:=IntToStr(Round((tmHeight-tmInternalLeading)*72 / VRES));
           if Items.IndexOf(c)=-1 then AddToList(c);
           result:=1;
         end;
   end
end;
procedure TForm1.DoList(FFontName:String);
var
   buffer:array[0..255] of Char;
  DC:HDC;
 begin
  ListBox1.Items.Clear;
   DC:=GetDC(0);
   StrPCopy(Buffer, FFontName);
   vres:=GetDeviceCaps(DC, LOGPIXELSY);
   EnumFontFamilies(DC, Buffer, @EnumFontFamiliesProc,
                    LongInt(ListBox1));
    ReleaseDC(0, DC);
 end;