win32-StretchDIBits
2021-03-02 18:28
标签:buffer lex 截图 ltm import har rndc fun main 使用StretchDIBits将位图数据传输到printer的dc中 上面是打印一个红色就× 也可以结合官方示例,将屏幕截图打印到printer的dc中 Note: 输出到printer截图会因为纸张的限制而被截取一部分,具体解决方法,参考: https://stackoverflow.com/questions/47642947/windows-gdi-scaling-a-screen-dc-to-a-printer-dc-without-modifying-the-draw-f win32-StretchDIBits 标签:buffer lex 截图 ltm import har rndc fun main 原文地址:https://www.cnblogs.com/strive-sun/p/13037528.html#include
int CaptureAnImage(HWND hWnd)
{
HDC hdcScreen;
HDC hdcWindow;
HDC hdcMemDC = NULL;
HBITMAP hbmScreen = NULL;
BITMAP bmpScreen;
// Retrieve the handle to a display device context for the client
// area of the window.
hdcScreen = GetDC(NULL);
hdcWindow = GetDC(hWnd);
// Create a compatible DC which is used in a BitBlt from the window DC
hdcMemDC = CreateCompatibleDC(hdcWindow);
if (!hdcMemDC)
{
MessageBox(hWnd, L"CreateCompatibleDC has failed", L"Failed", MB_OK);
// goto done;
}
// Get the client area for size calculation
RECT rcClient;
GetClientRect(hWnd, &rcClient);
//This is the best stretch mode
SetStretchBltMode(hdcWindow, HALFTONE);
//The source DC is the entire screen and the destination DC is the current window (HWND)
if (!StretchBlt(hdcWindow,
0, 0,
rcClient.right, rcClient.bottom,
hdcScreen,
0, 0,
GetSystemMetrics(SM_CXSCREEN),
GetSystemMetrics(SM_CYSCREEN),
SRCCOPY))
{
MessageBox(hWnd, L"StretchBlt has failed", L"Failed", MB_OK);
// goto done;
}
// Create a compatible bitmap from the Window DC
hbmScreen = CreateCompatibleBitmap(hdcWindow, rcClient.right - rcClient.left, rcClient.bottom - rcClient.top);
if (!hbmScreen)
{
MessageBox(hWnd, L"CreateCompatibleBitmap Failed", L"Failed", MB_OK);
// goto done;
}
// Select the compatible bitmap into the compatible memory DC.
SelectObject(hdcMemDC, hbmScreen);
// Bit block transfer into our compatible memory DC.
if (!BitBlt(hdcMemDC,
0, 0,
rcClient.right - rcClient.left, rcClient.bottom - rcClient.top,
hdcWindow,
0, 0,
SRCCOPY))
{
MessageBox(hWnd, L"BitBlt has failed", L"Failed", MB_OK);
// goto done;
}
// Get the BITMAP from the HBITMAP
GetObject(hbmScreen, sizeof(BITMAP), &bmpScreen);
BITMAPFILEHEADER bmfHeader;
BITMAPINFOHEADER bi;
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = bmpScreen.bmWidth;
bi.biHeight = bmpScreen.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = 32;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;
DWORD dwBmpSize = ((bmpScreen.bmWidth * bi.biBitCount + 31) / 32) * 4 * bmpScreen.bmHeight;
// Starting with 32-bit Windows, GlobalAlloc and LocalAlloc are implemented as wrapper functions that
// call HeapAlloc using a handle to the process‘s default heap. Therefore, GlobalAlloc and LocalAlloc
// have greater overhead than HeapAlloc.
HANDLE hDIB = GlobalAlloc(GHND, dwBmpSize);
char* lpbitmap = (char*)GlobalLock(hDIB);
// Gets the "bits" from the bitmap and copies them into a buffer
// which is pointed to by lpbitmap.
GetDIBits(hdcWindow, hbmScreen, 0,
(UINT)bmpScreen.bmHeight,
lpbitmap,
(BITMAPINFO*)&bi, DIB_RGB_COLORS);
PRINTDLG pdlg = { 0 };
pdlg.lStructSize = sizeof(pdlg);
pdlg.Flags = PD_RETURNDC;
if (PrintDlg(&pdlg) == TRUE)
{
HDC hPrinterDC = pdlg.hDC;
DOCINFO di;
ZeroMemory(&di, sizeof(di));
di.cbSize = sizeof(di);
di.lpszDocName = TEXT("Test");
if (StartDoc(hPrinterDC, &di) > 0)
{
if (StartPage(hPrinterDC) > 0)
{
int nPrinterWidth = GetDeviceCaps(hPrinterDC, HORZRES);
int nPrinterHeight = GetDeviceCaps(hPrinterDC, VERTRES);
int nLogPixelsXScreen = GetDeviceCaps(hdcScreen, LOGPIXELSX);
int nLogPixelsYScreen = GetDeviceCaps(hdcScreen, LOGPIXELSY);
int nLogPixelsXPrinter = GetDeviceCaps(hPrinterDC, LOGPIXELSX);
int nLogPixelsYPrinter = GetDeviceCaps(hPrinterDC, LOGPIXELSY);
int nScaleX = max(nLogPixelsXScreen, nLogPixelsXPrinter) / min(nLogPixelsXScreen, nLogPixelsXPrinter);
int nScaleY = max(nLogPixelsYScreen, nLogPixelsYPrinter) / min(nLogPixelsYScreen, nLogPixelsYPrinter);
SetMapMode(hPrinterDC, MM_ISOTROPIC);
SetWindowExtEx(hPrinterDC, nPrinterWidth, nPrinterHeight, 0);
SetViewportExtEx(hPrinterDC, nPrinterWidth, nPrinterHeight, 0);
SetViewportOrgEx(hPrinterDC, 0, 0, 0);
SetStretchBltMode(hPrinterDC, COLORONCOLOR);
StretchDIBits(hPrinterDC, 0, 0, bmpScreen.bmWidth * nScaleX, bmpScreen.bmHeight * nScaleY, 0, 0, bmpScreen.bmWidth, bmpScreen.bmHeight, lpbitmap, (LPBITMAPINFO)&bi, DIB_RGB_COLORS, SRCCOPY);
EndPage(hPrinterDC);
}
EndDoc(hPrinterDC);
}
}
//Clean up
done:
DeleteObject(hbmScreen);
DeleteObject(hdcMemDC);
ReleaseDC(NULL, hdcScreen);
ReleaseDC(hWnd, hdcWindow);
return 0;
}
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文章标题:win32-StretchDIBits
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