public static extern int StretchDIBits(HandleRef hdc, int XDest, int YDest, int nDestWidth, int nDestHeight, int XSrc, int YSrc, int nSrcWidth, int nSrcHeight, byte[] lpBits, ref NativeMethods.BITMAPINFO_FLAT lpBitsInfo, int iUsage, int dwRop);
/// <summary>
/// Call into native code to create compatible Device Independent Bitmap
/// </summary>
/// <param name="hdc">Source hdc</param>
/// <param name="ulWidth">Bitmap width</param>
/// <param name="ulHeight">Bitmap height</param>
/// <param name="ppvBits">Returned bits</param>
/// <returns>The handle to the new bitmap</returns>
private int CreateCompatibleDIB(int hdc, int ulWidth, int ulHeight, ref int ppvBits)
{
int hbmRet = NativeMethods.Nullint;
NativeMethods.BITMAPINFO_FLAT pbmi = new NativeMethods.BITMAPINFO_FLAT();
//
// Validate hdc.
//
if (hdc == NativeMethods.Nullint) {
throw new ArgumentNullException("hdc");
}
if (NativeMethods.GetObjectType(hdc) != NativeMethods.OBJ_DC ) {
throw new ArgumentException("hdc", "HDC must be screen DC!");
}
if (FillBitmapInfo(hdc, ref pbmi)) {
//
// Change bitmap size to match specified dimensions.
//
pbmi.bmiHeader_biWidth = ulWidth;
pbmi.bmiHeader_biHeight = ulHeight;
if (pbmi.bmiHeader_biCompression == NativeMethods.BI_RGB) {
pbmi.bmiHeader_biSizeImage = 0;
}
else {
if ( pbmi.bmiHeader_biBitCount == 16 )
pbmi.bmiHeader_biSizeImage = ulWidth * ulHeight * 2;
else if ( pbmi.bmiHeader_biBitCount == 32 )
pbmi.bmiHeader_biSizeImage = ulWidth * ulHeight * 4;
else
pbmi.bmiHeader_biSizeImage = 0;
}
pbmi.bmiHeader_biClrUsed = 0;
pbmi.bmiHeader_biClrImportant = 0;
//
// Create the DIB section. Let Win32 allocate the memory and return
// a pointer to the bitmap surface.
//
hbmRet = NativeMethods.CreateDIBSection(hdc, ref pbmi, NativeMethods.DIB_RGB_COLORS, ref ppvBits, NativeMethods.Nullint, 0);
if ( hbmRet == NativeMethods.Nullint ) {
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
return hbmRet;
}
public static extern int GetDIBits(IntPtr hdc, IntPtr hbm, int uStartScan, int cScanLines, byte[] lpvBits, ref NativeMethods.BITMAPINFO_FLAT bmi, int uUsage);
