This example will show how to indicate that the graphics device expects a 16-bit image with the image data in the low 12 bits. Also, this particular card expected the data to be top-down, unlike the usual GDI functions which expect the data to be upside-down.

The example is in C++/CLI because this is the most useful language for implementing these classes.

C#

Copy Code

// macro that calculates the number of bytes per line, rounding up to a multiple of 4 bytes  #define DIB_WIDTH_BYTES(pixels) ((((pixels) + 31) & ~31) >> 3)    Object^ myPaintCallbacks::GetDibInfoCallback(RasterImage^ image, array<Object^>^ Params)  {     // make sure the parameters are correct     if(Params->Length != 2 || image == nullptr)     {        throw gcnew RasterException(RasterExceptionCode::InvalidParameter);        return nullptr;     }     UInt32 uWidth = (UInt32)Params[1];     RasterPaintDibInfo^ pDibInfo = gcnew RasterPaintDibInfo;     if(pDibInfo == nullptr)     {        throw gcnew RasterException(RasterExceptionCode::NoMemory);        return nullptr;     }       pDibInfo->Default();     pDibInfo->BitsPerPixel = 16;          // paint using 16-bit data, although there are only 12 significant bits     pDibInfo->PlaneCount = 1;             // One plane     pDibInfo->BytesPerLine = DIB_WIDTH_BYTES(uWidth * 16);   // bytes per line is a multiple of 4 bytes     pDibInfo->ViewPerspective = RasterViewPerspective::TopLeft; // the data should be TOP_LEFT, not BOTTOM_LEFT like the data in the regular GDI functions     pDibInfo->Order = RasterByteOrder::Gray;         // gray bitmap       // indicate that the data should be in the low 12 bits     pDibInfo->Flags = RasterPaintDibInfoFlags::LowHighBitValid;     pDibInfo->LowBit = 0;     pDibInfo->HighBit = 11;       return pDibInfo;  }

The user will typically allocate this class and return it from the RasterImagePaintCallbackFunction.GetDibInfoCallback callback.

System.Object
   Leadtools.RasterPaintDibInfo

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

Reference