hbitmap

问题 Hello and good day to everyone, my final target is to draw a PNG file including alpha onto the screen - that means not into an own window but just somewhere on the desktop. The part to load PNG's into a HBITMAP works now (tested that in a diffrent way) but I don't manage to draw it including alpha. As far as I've heard the best way to do this would be using alyered windows. So I wroked a lot to redo a couple of examples and tiny tutorials. The following code compiles without problems and

问题 In this function, after about 90 calls (it's called in a loop and the idea is to load in a separate image each time, but I have kept it to one image for simplicity).The global variables now changed to local ones. void CDLP_Printer_ControlDlg::DisplayBMPfromSVG(CString& strDsiplayFile) { HBITMAP hbmp_temp = (HBITMAP)::LoadImage(0, strDsiplayFile, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); if (!hbmp_temp) { //hbmp_temp = ::LoadBitmap(AfxGetInstanceHandle(), MAKEINTRESOURCE(IDB_BITMAP1)); ActionList

问题 Now that QPixmap::toWinHBITMAP() has been deprecated, I can't find a way to get an HBITMAP from a QPixmap (or QImage). Googling, I found there's a function called qt_pixmapToWinHBITMAP() which seems would do what I need, but I can't find what module I should enable -if any- in my .pro file or what header I should include to use it, or perhaps something else. The reason I need a HBITMAP is to create a video using VFW. Of course, I'd love to be able to do that using only Qt. There's the

问题 I need to create a HBITMAP from data returned by a glReadPixels() call: HDC hCompDC = CreateCompatibleDC(NULL); HDC hDC = GetDC(); m_hClipboardBitmap = CreateCompatibleBitmap(hDC, size.cx, size.cy); if ( m_hClipboardBitmap == NULL ) { throw runtime_error( "Unable to create bitmap." ); } HBITMAP hOldBm = (HBITMAP) SelectObject( hCompDC, m_hClipboardBitmap ); int numberOfBytes = 4 * size.cx * size.cy; unsigned char *pPixelData = new unsigned char[numberOfBytes]; ::glReadPixels(minimum.x,

问题 I have an HBITMAP containing alpha channel data. I can successfully render this using the ::AlphaBlend GDI function. However, when I call the ::GetPixel GDI function, I never get back values with an alpha component. The documentation does say that it returns the RGB value of the pixel. Is there a way to retrieve the alpha channel values for pixels in an HBITMAP ? I want to be able to detect when to use ::AlphaBlend, and when to use an old-school method for treating a particular colour in the

问题 I apologize upfront; I'm new to c and I really don't know what I'm doing. I am trying to capture and display a screen shot using Windows 7 and c. I know it sounds dumb, eventually I will need each of these functions in different programs, the one that captures the screen will send the image to the one that displays it but for now I am just trying to get them both to work in one program. Here is the code I've put together so far: #include <windows.h> bool ScreenCapture(int x, int y, int width,

问题 I have an existing buffer full of (DIB) bitmap data, i.e. width x height x 4 bytes (RGBA) in size. What I want to do is draw this bitmap to the screen, but looking at the CreateBitmap... / CreateDIB... functions, they don't appear to do what I'm looking for. I don't want to copy the memory in, I want to retain access to it, so I can continue to write to it in the next frame (without incurring a penalty for copying the data). Does such a method exist, or do I have to create a new bitmap and

问题 I want to create HBITMAP from byte array with JPEG format. I have searched but I only can create it from bitmap file as HBITMAP hbm = (HBITMAP)LoadImage(NULL,"fileName",IMAGE_BITMAP,0,0,LR_LOADFROMFILE|LR_CREATEDIBSECTION); Can someone show me how to do it? 回答1: Just use GDIplus. It supports loading JPEGs, and some other stuff feels much more logically http://msdn.microsoft.com/en-us/library/ms533830%28v=vs.85%29.aspx Use "Bitmap" class. When you have the jpeg in a buffer, you need to read it

问题 In my windows-only program, I use a third-party library, which returns a HBITMAP . Is there a way to initialize a QImage from its contents, i.e. to convert it to a QImage ? 回答1: This is the way to do it for Qt 4 (QtGui): QImage image(QPixmap::fromWinHBITMAP(hBitmap).toImage()); This is the way to do it for Qt 5 (QtWinExtras): QPixmap pixmap = QtWin::fromHBITMAP(hBitmap); QImage image = pixmap.toImage(); // or QtWin::imageFromHBITMAP(hdc, hBitmap, width, height) 回答2: OK, this seems to work for

问题 This question already has answers here : Save HBITMAP to *.bmp file using only Win32 (4 answers) Closed 5 years ago . Ok, whole story is, I am trying to use Leptonica+Tesseract OCR in C++ to take a screenshot, save it to a *.bmp file, then load it back up to OCR with it. I won't need to do this frequently, but as I cannot seem to copy the screenshot data directly into a Leptonica PIX structure, I need to save it to a file first..actually a solution to this would be preferably. Here's some