Newsgroup: it.comp.lang.visual-basic
Titolo: [?] Esempi di utilizzo API grafiche

ciao a tutti, mi servirebbero alcuni esempi di ultilizzo di api grafiche, in
particolare della funzione
GetDIBits
Il mio progblema è quello di inserire una immagine bitmap da file, su un
documento rtf. Dalla docuemntazione Microsoft ho dedotto che i dati da
memorizzare sono proprio quelli ritornati da questa funzione, ma non ho
trovato molti chiarimenti su come si utilizza.
Grazie a chi può aiutarmi
ciao a tutti e buon lavoro

 ha scritto

dall'apiguide, free, di 
www.allapi.net
tiralo giu'
ciao
Private Const BI_RGB = 0&
Private Const DIB_RGB_COLORS = 0 ' color table in RGBs
Private Type BITMAPINFOHEADER '40 bytes
biSize As Long
biWidth As Long
biHeight As Long
biPlanes As Integer
biBitCount As Integer
biCompression As Long
biSizeImage As Long
biXPelsPerMeter As Long
biYPelsPerMeter As Long
biClrUsed As Long
biClrImportant As Long
End Type
Private Type RGBQUAD
rgbBlue As Byte
rgbGreen As Byte
rgbRed As Byte
rgbReserved As Byte
End Type
Private Type BITMAPINFO
bmiHeader As BITMAPINFOHEADER
bmiColors As RGBQUAD
End Type
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As
Long) As Long
Private Declare Function CreateDIBSection Lib "gdi32" (ByVal hdc As
Long, pBitmapInfo As BITMAPINFO, ByVal un As Long, ByVal lplpVoid As
Long, ByVal handle As Long, ByVal dw As Long) As Long
Private Declare Function GetDIBits Lib "gdi32" (ByVal aHDC As Long,
ByVal hBitmap As Long, ByVal nStartScan As Long, ByVal nNumScans As
Long, lpBits As Any, lpBI As BITMAPINFO, ByVal wUsage As Long) As Long
Private Declare Function SetDIBitsToDevice Lib "gdi32" (ByVal hdc As
Long, ByVal x As Long, ByVal y As Long, ByVal dx As Long, ByVal dy As
Long, ByVal SrcX As Long, ByVal SrcY As Long, ByVal Scan As Long,
ByVal NumScans As Long, Bits As Any, BitsInfo As BITMAPINFO, ByVal
wUsage As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long,
ByVal hObject As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As
Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As
Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long,
ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight
As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long,
ByVal dwRop As Long) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As
Long
Dim iBitmap As Long, iDC As Long
Private Sub Form_Paint()
'KPD-Team 2000
'URL: 
http://www.allapi.net/
'E-Mail: KPD...@Allapi.net
'-> Compile this code for better performance
Dim bi24BitInfo As BITMAPINFO, bBytes() As Byte, Cnt As Long
With bi24BitInfo.bmiHeader
.biBitCount = 24
.biCompression = BI_RGB
.biPlanes = 1
.biSize = Len(bi24BitInfo.bmiHeader)
.biWidth = 100
.biHeight = 100
End With
ReDim bBytes(1 To bi24BitInfo.bmiHeader.biWidth *
bi24BitInfo.bmiHeader.biHeight * 3) As Byte
iDC = CreateCompatibleDC(0)
iBitmap = CreateDIBSection(iDC, bi24BitInfo, DIB_RGB_COLORS, ByVal 0&,
ByVal 0&, ByVal 0&)
SelectObject iDC, iBitmap
BitBlt iDC, 0, 0, bi24BitInfo.bmiHeader.biWidth,
bi24BitInfo.bmiHeader.biHeight, GetDC(0), 0, 0, vbSrcCopy
GetDIBits iDC, iBitmap, 0, bi24BitInfo.bmiHeader.biHeight, bBytes(1),
bi24BitInfo, DIB_RGB_COLORS
For Cnt = LBound(bBytes) To UBound(bBytes)
If bBytes(Cnt) < 50 Then
bBytes(Cnt) = 0
Else
bBytes(Cnt) = bBytes(Cnt) - 50
End If
Next Cnt
SetDIBitsToDevice Me.hdc, 0, 0, bi24BitInfo.bmiHeader.biWidth,
bi24BitInfo.bmiHeader.biHeight, 0, 0, 0,
bi24BitInfo.bmiHeader.biHeight, bBytes(1), bi24BitInfo, DIB_RGB_COLORS
DeleteDC iDC
DeleteObject iBitmap
End Sub