VB Forum / Win API / March 2006

Gary <Gary@discussions.microsoft.com> schrieb im Beitrag
<71AFA002-22B4-41BE-992C-19C06DEDAC22@microsoft.com>...

GLYPHSET is a structure with an array of WCRANGE structures (field
"ranges"). This means that the size of this structure is variable. On the
one hand it is not possible to get the count of items of the array without
getting the GLYPHSET structure, on the other hand it is not possible to get
the GLYPHSET structure without knowing its total size, i.e. the count of
items of the array.
Therefore the function GetFontUnicodeRanges() provides another way: Setting
the second parameter to NULL lets the function return the total size of the
GLYPHSET structure. This will not help you to get the full GLYPHSET
structure in VB directly, but by this you can retrieve it indirectly.
Sample code ('on the fly'):

Private Declare Function GetFontUnicodeRanges _
                        Lib "gdi32.dll" _
                        ( _
                          ByVal hDC As Long, _
                          pGLYPHSET As Any _
                        ) As Long

Private Declare Sub CopyMemory _
                   Lib "kernel32" Alias "RtlMoveMemory" _
                   ( _
                     pDestination As Any, _
                     pSource As Any, _
                     ByVal lByteCount As Long _
                   )

Private type typWCRANGE
 iLow As Integer
 iGlyphs As Integer
End Type

Private type typGLYPHSET
 lStructSize As Long
 lAccel As Long
 lGlyphsSupported As Long
 lRanges As Long
 aRANGE() As typWCRANGE
End Type

Dim abData() As Byte, lIndexData As Long
Dim lResult As Long, lCount As Long, lIndex As Long
Dim GS as

lResult& = GetFontUnicodeRanges(hDC, ByVal 0&)
If lResult& Then
 ReDim abData(0 To (lResult& - 1)) As Byte
 lResult& = GetFontUnicodeRanges(hDC, abData(LBound(abData)))
 If lResult& Then
   lIndexData& = LBound(abData)
   lCount& = 4& * 4&
   Call CopyMemory(GS, abData(lIndexData), lCount&)
   lIndexData& = lIndexData& + lCount&
   With GS
     If .lRanges& Then
       ReDim .aRANGE(0 To (.lRanges& - 1)) As typWCRANGE
       lIndex& = LBound(.aRANGE)
       lCount = .lRanges&
       While lCount&
         Call CopyMemory(.aRANGE(lIndex&), abData(lIndexData&),
Len(.aRANGE(lIndex&)))
         lIndexData& = lIndexData& + Len(.aRANGE(lIndex&))
         lIndex& = lIndex& + 1
         lCount& = lCount& - 1
       Wend
     End If
   End With
 End If
End If