----在具體應用中可能會要處理無格式的圖像,在VB中可利用API函數SetDIBitsToDevice實現這一功能.下面是我在工作中用到的顯示256X256大小,256灰度級圖像的程序.
DeclareFunctionGlobalAllocLib"kernel32"(ByValwFlagsAsLong,ByValdwBytesAsLong)AsLong
DeclareFunctionGlobalLockLib"kernel32"(ByValhMemAsLong)AsLong
DeclareFunctionGlobalUnlockLib"kernel32"(ByValhMemAsLong)AsLong
DeclareFunctionGlobalFreeLib"kernel32"(ByValhMemAsLong)AsLong
DeclareFunctionDeleteDCLib"gdi32"(ByValHDCAsLong)AsLong
DeclareFunctionDeleteObjectLib"gdi32"(ByValhObjectAsLong)AsLong
DeclareFunctionSetDIBitsToDeviceLib"gdi32"(ByValHDCAsLong,ByValxAsLong,ByValyAsLong,ByValdxAsLong,ByValdyAsLong,ByValSrcXAsLong,ByValSrcYAsLong,ByValScanAsLong,ByValNumScansAsLong,BitsAsAny,BitsInfoAsBITMAPINFO,ByValwUsageAsLong)AsLong
Typergbquad
rgbBlueAsByte
rgbGreenAsByte
rgbRedAsByte
rgbReservedAsByte
EndType
TypePALETTEENTRY
peRedAsByte
peGreenAsByte
peBlueAsByte
peFlagsAsByte
EndType
TypeBITMAPFILEHEADER
bfTypeAsInteger
bfSizeAsLong
bfReserved1AsInteger
bfReserved2AsInteger
bfOffBitsAsLong
EndType
TypeBITMAPINFOHEADER
biSizeAsLong
biWidthAsLong
biHeightAsLong
biPlanesAsInteger
biBitCountAsInteger
biCompressionAsLong
biSizeImageAsLong
biXPelsPerMeterAsLong
biYPelsPerMeterAsLong
biClrUsedAsLong
biClrImportantAsLong
EndType
TypeBITMAPINFO
bmiHeaderAsBITMAPINFOHEADER
bmiColors(0To255)Asrgbquad
EndType
GlobalConstSRCCOPY=&HCC0020'dest=source
GlobalConstsrcand=&H8800C6'dest=sourceanddest
GlobalConstsrcor=&HEE0086'dest=sourceordest
PublicConstCOLORONCOLOR=3
PublicConstDIB_RGB_COLORS=0'colortableinRGBs
PublicConstDIB_PAL_COLORS=1'
colortableinpaletteindices
GlobalConstGMEM_MOVEABLE=&H2
'--------以上為定義部分,可放在一個BAS文件中--------
DimxAsLong,iiAsInteger
Dimw1AsLong,h1AsLong
Dimbitmapinfo_hAsBITMAPINFOHEADER,
bitmapfile_hAsBITMAPFILEHEADER
DimlpInitInfoAsBITMAPINFO
Dimt_rgbquad(0To255)Asrgbquad
DimpLogPalAsLOGPALETTE
DimlengAsLong
Dimt_buf()AsByte'圖像數據buffer
OnErrorGoToError_process
'Setuperrorhandler.
'Openthefile
pfile1$="c:fcg est.d"
'test.d為256X256大小,256灰度級的無格式圖像文件
fd=FreeFile
w1=256'圖像寬度
h1=256'圖像高度
leng=w1*h1
ReDimt_buf(leng)AsByte
Openpfile1$ForBinaryAs#fd
Get#fd,,t_buf
Close'Closethefile
leng=w1*h1
bitmapfile_h.bfType=19778'"BM"
bitmapfile_h.bfSize=1078 h1*w1
bitmapfile_h.bfReserved1=0
bitmapfile_h.bfReserved2=0
bitmapfile_h.bfOffBits=1078
bitmapinfo_h.biSize=40
bitmapinfo_h.biWidth=w1
bitmapinfo_h.biHeight=h1
bitmapinfo_h.biPlanes=1
bitmapinfo_h.biBitCount=8
bitmapinfo_h.biCompression=0
bitmapinfo_h.biSizeImage=0
bitmapinfo_h.biXPelsPerMeter=0
bitmapinfo_h.biYPelsPerMeter=0
bitmapinfo_h.biClrUsed=256
Forii=0To255'設置色表為256灰度
t_rgbquad(ii).rgbBlue=CByte(ii)
t_rgbquad(ii).rgbGreen=CByte(ii)
t_rgbquad(ii).rgbRed=CByte(ii)
't_rgbquad.rgbReserved=0
Nextii
lpInitInfo.bmiHeader=bitmapinfo_h
Forii=0To255
lpInitInfo.bmiColors(ii)=t_rgbquad(ii)
Nextii
'picture1為一個picture控件,
用於顯示無格式256灰度級圖像
x=SetDIBitsToDevice(picture1.HDC,0,0,
w1,h1,0,0,0,h1,t_buf(0),lpInitInfo,
0)'顯示圖像
x=GlobalUnlock(hPal)'釋放資源
x=GlobalFree(hPal)
GoToNormal_exit
Error_process:
Msgbox"程序運行出錯!"
Normal_exit:->
