bool screenshot(HWND hwnd, const char *filename) {
	int     nWidth  = GetSystemMetrics(SM_CXSCREEN);
	int     nHeight = GetSystemMetrics(SM_CYSCREEN);

	HDC     hdc     = GetDC(hwnd);
	HDC     memDC   = CreateCompatibleDC(hdc);
	HBITMAP hbm     = CreateCompatibleBitmap(hdc, nWidth, nHeight);
	HBITMAP hbmOld  = (HBITMAP)SelectObject(memDC, hbm);

	BitBlt(memDC, 0, 0, nWidth, nHeight, hdc, 0, 0, SRCCOPY);

	BITMAPINFO bmi;

	ZeroMemory(&bmi, sizeof(bmi));

	bmi.bmiHeader.biSize         = sizeof(BITMAPINFOHEADER);
	bmi.bmiHeader.biWidth        = nWidth;
	bmi.bmiHeader.biHeight       = nHeight;
	bmi.bmiHeader.biBitCount     = 24;
	bmi.bmiHeader.biPlanes       = 1;
	bmi.bmiHeader.biCompression  = BI_RGB;
	bmi.bmiHeader.biSizeImage    = bmi.bmiHeader.biBitCount * nWidth * nHeight / 8;

	BYTE *pbBits = new BYTE[bmi.bmiHeader.biSizeImage];

	GetDIBits( memDC, 
				 hbm,
				 0,
				 bmi.bmiHeader.biHeight,
				 pbBits,
				 &bmi,
				 DIB_RGB_COLORS );

				BITMAPFILEHEADER bfh;

				bfh.bfType      = ('M' << 8) + 'B';
				bfh.bfSize      = sizeof(BITMAPFILEHEADER)  +
								  bmi.bmiHeader.biSizeImage +
								  sizeof(BITMAPINFOHEADER); 
				bfh.bfReserved1 = 0;
				bfh.bfReserved2 = 0;
				bfh.bfOffBits   = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

				HANDLE hfile = CreateFile( filename,
										   GENERIC_WRITE,
										   0,
										   0,
										   OPEN_ALWAYS,
										   0,
										   0 ); 

				DWORD dwWritten;

				WriteFile(hfile,&bfh,           sizeof(bfh),               &dwWritten, NULL); 
				WriteFile(hfile,&bmi.bmiHeader, sizeof(BITMAPINFOHEADER),  &dwWritten, NULL); 
				WriteFile(hfile,pbBits,         bmi.bmiHeader.biSizeImage, &dwWritten, NULL); 

				CloseHandle(hfile); 

				SelectObject(memDC, hbmOld);
				DeleteDC(memDC);
				ReleaseDC(hwnd,hdc); 
				DeleteObject(hbm);

				delete[] pbBits;
				return true;
}

Vielen Dank im Voraus!

MrScreenshot

Das war der Code den ich zu Testzwecken ausprobiert hatte.
Dies ist der richtige Code den ich zur Zeit nutze und bei dem das beschriebene Problem auftritt!
**

/*
 !!! DER RICHTIGE CODE !!!
*/
bool screenshot(HWND hwnd, const char *filename) {
	RECT rt;
	HDC hdc = GetWindowDC(hwnd);
	GetWindowRect(hwnd, &rt);
	int width = rt.right - rt.left;
	int height = rt.bottom - rt.top;

	HDC hdc2;
	HBITMAP aBmp;
	BITMAPINFO bi;
	HGDIOBJ OldObj;

	void *dibvalues;

	HANDLE fileHandle;

	BITMAPFILEHEADER bmfh;
	BITMAPINFOHEADER bmih;
	DWORD bytes_write;
	DWORD bytes_written;

	hdc2 = CreateCompatibleDC(hdc);

	ZeroMemory(&bmih,sizeof(BITMAPINFOHEADER));

	bmih.biSize=sizeof(BITMAPINFOHEADER);
	bmih.biHeight=height;
	bmih.biWidth=width;
	bmih.biPlanes=1;
	bmih.biBitCount=24;
	bmih.biCompression = BI_RGB;
	bmih.biSizeImage = ((((bmih.biWidth * bmih.biBitCount) + 31) & ~31) >> 3) * bmih.biHeight;
	bmih.biXPelsPerMeter = 0;
	bmih.biYPelsPerMeter = 0;
	bmih.biClrImportant = 0;

	bi.bmiHeader = bmih;

	aBmp = CreateDIBSection(hdc,&bi,DIB_RGB_COLORS,(void**)&dibvalues,NULL,NULL);

	if (!aBmp) {
		return false;
	}

	OldObj = SelectObject(hdc2,aBmp);

	BitBlt(hdc2,0,0,width,height,hdc,0,0,SRCCOPY);

	ZeroMemory(&bmfh,sizeof(BITMAPFILEHEADER));

	bmfh.bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
	bmfh.bfSize = (3*bmih.biHeight*bmih.biWidth)+sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
	bmfh.bfType = 0x4d42;
	bmfh.bfReserved1 = 0;
	bmfh.bfReserved2 = 0;

	fileHandle=CreateFile(filename,GENERIC_READ | GENERIC_WRITE,(DWORD)0,NULL,

	CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,(HANDLE) NULL);

	if (fileHandle==INVALID_HANDLE_VALUE) {
		return false;
	}

	bytes_write = sizeof(BITMAPFILEHEADER);

	if (!WriteFile(fileHandle,(void*)&bmfh,bytes_write,&bytes_written,NULL)) {
		return false;
	}

	bytes_write = sizeof(BITMAPINFOHEADER);

	if (!WriteFile(fileHandle,(void*)&bmih,bytes_write,&bytes_written,NULL)) {
		return false;
	}

	bytes_write = bmih.biSizeImage;

	if (!WriteFile(fileHandle,(void*)dibvalues,bytes_write,&bytes_written,NULL)) {
		return false;
	}

	CloseHandle(fileHandle);

	DeleteObject(SelectObject(hdc2,OldObj));
	DeleteDC(hdc2);
	ReleaseDC(hwnd,hdc); 

	return true;
}

Nochmals Vielen Dank im Voraus!

MrScreenshot

Grüße