// ported form VB6 (Ctls\PortUtil\StdCtl.cpp:6176)
private unsafe bool DICopy(IntPtr hdcDest, IntPtr hdcSrc, RECT rect, bool bStretch)
{
long i;
// Get the bitmap from the DC by selecting in a 1x1 pixel temp bitmap
IntPtr hNullBitmap = SafeNativeMethods.CreateBitmap(1, 1, 1, 1, IntPtr.Zero);
if (hNullBitmap == IntPtr.Zero)
{
return(false);
}
try
{
IntPtr hBitmap = Gdi32.SelectObject(hdcSrc, hNullBitmap);
if (hBitmap == IntPtr.Zero)
{
return(false);
}
// Restore original bitmap
Gdi32.SelectObject(hdcSrc, hBitmap);
if (!Gdi32.GetObjectW(hBitmap, out Gdi32.BITMAP bmp))
{
return(false);
}
NativeMethods.BITMAPINFO_FLAT lpbmi = new NativeMethods.BITMAPINFO_FLAT
{
bmiHeader_biSize = Marshal.SizeOf <NativeMethods.BITMAPINFOHEADER>(),
bmiHeader_biWidth = bmp.bmWidth,
bmiHeader_biHeight = bmp.bmHeight,
bmiHeader_biPlanes = 1,
bmiHeader_biBitCount = (short)bmp.bmBitsPixel,
bmiHeader_biCompression = NativeMethods.BI_RGB,
bmiHeader_biSizeImage = 0, //Not needed since using BI_RGB
bmiHeader_biXPelsPerMeter = 0,
bmiHeader_biYPelsPerMeter = 0,
bmiHeader_biClrUsed = 0,
bmiHeader_biClrImportant = 0,
bmiColors = new byte[NativeMethods.BITMAPINFO_MAX_COLORSIZE * 4]
};
// Include the palette for 256 color bitmaps
long iColors = 1 << (bmp.bmBitsPixel * bmp.bmPlanes);
if (iColors <= 256)
{
byte[] aj = new byte[Marshal.SizeOf <NativeMethods.PALETTEENTRY>() * 256];
SafeNativeMethods.GetSystemPaletteEntries(hdcSrc, 0, (int)iColors, aj);
fixed(byte *pcolors = lpbmi.bmiColors)
{
fixed(byte *ppal = aj)
{
NativeMethods.RGBQUAD * prgb = (NativeMethods.RGBQUAD *)pcolors;
NativeMethods.PALETTEENTRY *lppe = (NativeMethods.PALETTEENTRY *)ppal;
// Convert the palette entries to RGB quad entries
for (i = 0; i < (int)iColors; i++)
{
prgb[i].rgbRed = lppe[i].peRed;
prgb[i].rgbBlue = lppe[i].peBlue;
prgb[i].rgbGreen = lppe[i].peGreen;
}
}
}
}
// Allocate memory to hold the bitmap bits
long bitsPerScanLine = bmp.bmBitsPixel * (long)bmp.bmWidth;
long bytesPerScanLine = (bitsPerScanLine + 7) / 8;
long totalBytesReqd = bytesPerScanLine * bmp.bmHeight;
byte[] lpBits = new byte[totalBytesReqd];
// Get the bitmap bits
int diRet = SafeNativeMethods.GetDIBits(hdcSrc, hBitmap, 0, bmp.bmHeight, lpBits,
ref lpbmi, NativeMethods.DIB_RGB_COLORS);
if (diRet == 0)
{
return(false);
}
// Set the destination coordiates depending on whether stretch-to-fit was chosen
int xDest, yDest, cxDest, cyDest;
if (bStretch)
{
xDest = rect.left;
yDest = rect.top;
cxDest = rect.right - rect.left;
cyDest = rect.bottom - rect.top;
}
else
{
xDest = rect.left;
yDest = rect.top;
cxDest = bmp.bmWidth;
cyDest = bmp.bmHeight;
}
// Paint the bitmap
int iRet = SafeNativeMethods.StretchDIBits(hdcDest,
xDest, yDest, cxDest, cyDest, 0, 0, bmp.bmWidth, bmp.bmHeight,
lpBits, ref lpbmi, NativeMethods.DIB_RGB_COLORS, NativeMethods.SRCCOPY);
if (iRet == NativeMethods.GDI_ERROR)
{
return(false);
}
}
finally
{
Gdi32.DeleteObject(hNullBitmap);
}
return(true);
}