在VB6中保存单色(1Bit)位图(VB6代码）

Option Explicit

Private Const DIB_RGB_COLORS As Long = 0
Private Const SRCCOPY As Long = &HCC0020
Private Const BI_RGB As Long = 0&

Private Type BITMAPINFOHEADER
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 Type BITMAP
bmType As Long
bmWidth As Long
bmHeight As Long
bmWidthBytes As Long
bmPlanes As Integer
bmBitsPixel As Integer
bmBits As Long
End Type

Private Declare Function CreateCompatibleDC Lib "gdi32.dll" ( _
ByVal hdc As Long) As Long
Private Declare Function CreateCompatibleBitmap Lib "gdi32.dll" ( _
ByVal hdc As Long, _
ByVal nWidth As Long, _
ByVal nHeight As Long) As Long
Private Declare Function SelectObject Lib "gdi32.dll" ( _
ByVal hdc As Long, _
ByVal hObject As Long) As Long
Private Declare Function BitBlt Lib "gdi32.dll" ( _
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 GetDIBits Lib "gdi32.dll" ( _
ByVal aHDC As Long, _
ByVal hBitmap As Long, _
ByVal nStartScan As Long, _
ByVal nNumScans As Long, _
ByRef lpBits As Any, _
ByRef lpBI As BITMAPINFO, _
ByVal wUsage As Long) As Long
Private Declare Function DeleteDC Lib "gdi32.dll" ( _
ByVal hdc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32.dll" ( _
ByVal hObject As Long) As Long
Private Declare Function GetBitmapObject Lib "gdi32" Alias "GetObjectA" ( _
ByVal hBitmap As Long, _
ByVal cbBuffer As Long, _
ByRef destBmp As Any) As Long

Private Sub SavePictureBW(ByVal ctrl As PictureBox, ByVal destfile As String)
Dim hdcMono As Long, hbmpMono As Long, hbmpOld As Long, dxBlt As Long, dyBlt As Long, success As Long
Dim numscans As Long, byteswide As Long, totalbytes As Long, lfilesize As Long
Dim bmpsrc As BITMAP, bmpdst As BITMAP
Dim bInfo As BITMAPINFO
Dim bitmaparray() As Byte, fileheader() As Byte
Dim ff As Integer, by8

'Object's scalemode must be Pixel.
dxBlt = ctrl.ScaleWidth
dyBlt = ctrl.ScaleHeight

'Create monochrome bitmap from control.
hdcMono = CreateCompatibleDC(0)
hbmpMono = CreateCompatibleBitmap(hdcMono, dxBlt, dyBlt)
success = GetBitmapObject(hbmpMono, Len(bmpsrc), bmpsrc)
hbmpOld = SelectObject(hdcMono, hbmpMono)
success = BitBlt(hdcMono, 0, 0, dxBlt, dyBlt, ctrl.hdc, 0, 0, SRCCOPY)

'Calculate array size needed for bitmap bits (dword aligned)
numscans = dyBlt
by8 = dxBlt / 8
If (dxBlt Mod 8) = 0 And (by8 Mod 4) = 0 Then
byteswide = by8
Else
byteswide = (Int(by8) + 4) - (Int(by8) Mod 4)
End If
totalbytes = numscans * byteswide
ReDim bitmaparray(1 To totalbytes)

'Set BITMAPINFO values to pass to GetDIBits function.
With bInfo
.bmiHeader.biSize = Len(.bmiHeader)
.bmiHeader.biWidth = bmpsrc.bmWidth
.bmiHeader.biHeight = bmpsrc.bmHeight
.bmiHeader.biPlanes = bmpsrc.bmPlanes
.bmiHeader.biBitCount = bmpsrc.bmBitsPixel
.bmiHeader.biCompression = BI_RGB
End With

success = GetDIBits(hdcMono, ctrl.Image, 0, numscans, bitmaparray(1), bInfo, DIB_RGB_COLORS)

'bitmaparray should now contain bitmap bit data. Now create bitmap file header.
ReDim fileheader(1 To &H3E)
fileheader(1) = &H42 'B
fileheader(2) = &H4D 'M
lfilesize = UBound(fileheader) + UBound(bitmaparray)
fileheader(3) = lfilesize And 255
fileheader(4) = (lfilesize \ 256) And 255
fileheader(5) = (lfilesize \ 65536) And 255
fileheader(6) = (lfilesize \ 16777216) And 255
fileheader(11) = &H3E 'offset
fileheader(15) = &H28 'size of bitmapinfoheader
fileheader(19) = dxBlt And 255
fileheader(20) = (dxBlt \ 256) And 255
fileheader(21) = (dxBlt \ 65536) And 255
fileheader(22) = (dxBlt \ 16777216) And 255
fileheader(23) = dyBlt And 255
fileheader(24) = (dyBlt \ 256) And 255
fileheader(25) = (dyBlt \ 65536) And 255
fileheader(26) = (dyBlt \ 16777216) And 255
fileheader(27) = 1
fileheader(29) = 1
fileheader(35) = UBound(bitmaparray) And 255
fileheader(36) = (UBound(bitmaparray) \ 256) And 255
fileheader(37) = (UBound(bitmaparray) \ 65536) And 255
fileheader(38) = (UBound(bitmaparray) \ 16777216) And 255
fileheader(47) = 2
fileheader(51) = 2
fileheader(59) = &HFF
fileheader(60) = &HFF
fileheader(61) = &HFF

ff = FreeFile
Open destfile For Binary Access Write As #ff
Put #ff, , fileheader
Put #ff, , bitmaparray
Close #ff

' Clean up
Call SelectObject(hdcMono, hbmpOld)
Call DeleteDC(hdcMono)
Call DeleteObject(hbmpMono)
End Sub

Private Sub Command1_Click()
Call SavePictureBW(Picture1, "d:\123.bmp")
End Sub