摘要:Save DC to a bitmap
void CaptureScreen(HWND window, const char* filename) 
{ 
// get screen rectangle RECT windowRect; GetWindowRect(window, &windowRect); // bitmap dimensions int bitmap_dx = windowRect.right - windowRect.left; int bitmap_dy = windowRect.bottom - windowRect.top; // create file ofstream file(filename, ios::binary); if(!file) return; // save bitmap file headers BITMAPFILEHEADER fileHeader; BITMAPINFOHEADER infoHeader; fileHeader.bfType = 0x4d42; fileHeader.bfSize = 0; fileHeader.bfReserved1 = 0; fileHeader.bfReserved2 = 0; fileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER); infoHeader.biSize = sizeof(infoHeader); infoHeader.biWidth = bitmap_dx; infoHeader.biHeight = bitmap_dy; infoHeader.biPlanes = 1; infoHeader.biBitCount = 24; infoHeader.biCompression = BI_RGB; infoHeader.biSizeImage = 0; infoHeader.biXPelsPerMeter = 0; infoHeader.biYPelsPerMeter = 0; infoHeader.biClrUsed = 0; infoHeader.biClrImportant = 0; file.write((char*)&fileHeader, sizeof(fileHeader)); file.write((char*)&infoHeader, sizeof(infoHeader)); // dibsection information BITMAPINFO info; info.bmiHeader = infoHeader; // ------------------ // THE IMPORTANT CODE // ------------------ // create a dibsection and blit the window contents to the bitmap HDC winDC = GetWindowDC(window); HDC memDC = CreateCompatibleDC(winDC); BYTE* memory = 0; HBITMAP bitmap = CreateDIBSection(winDC, &info, DIB_RGB_COLORS, (void**)&memory, 0, 0); SelectObject(memDC, bitmap); BitBlt(memDC, 0, 0, bitmap_dx, bitmap_dy, winDC, 0, 0, SRCCOPY); DeleteDC(memDC); ReleaseDC(window, winDC); // save dibsection data int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy; file.write(memory, bytes); DeleteObject(bitmap); 
}