抓屏示例
以下示例程序功能为：抓取整个屏幕并保存为D:\\1234.bmp
#include <windows.h>#include <iostream>using namespace std;//// 抓取屏幕图像存入DDB位图//HBITMAP CaptureScreenToDDB(){HDC hdcScreen = NULL;HDC hdcMem = NULL;HBITMAP hBitmap = NULL;HBITMAP hOldBitmap = NULL;int xScreenRes = 0;int yScreenRes = 0;// 创建屏幕设备描述表hdcScreen = ::CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);// 获取屏幕分辨率xScreenRes = ::GetDeviceCaps(hdcScreen, HORZRES);yScreenRes = ::GetDeviceCaps(hdcScreen, VERTRES);// 创建位图并拷贝屏幕至位图hdcMem = ::CreateCompatibleDC(hdcScreen);hBitmap = ::CreateCompatibleBitmap(hdcScreen, xScreenRes, yScreenRes);hOldBitmap = (HBITMAP)::SelectObject(hdcMem, hBitmap);::BitBlt(hdcMem, 0, 0, xScreenRes, yScreenRes, hdcScreen, 0, 0, SRCCOPY);hBitmap = (HBITMAP)::SelectObject(hdcMem, hOldBitmap);// 释放资源::DeleteDC(hdcMem);::DeleteDC(hdcScreen);return hBitmap;}//// 保存DDB位图成本地DIB位图文件//int SaveDDBToFile(HBITMAP hBitmap, HDC hdc, TCHAR name[]){// 获取位图信息BITMAP bm;::GetObject(hBitmap, sizeof(bm), &bm);// 计算位图文件每个字节所占的bit数int iBitsPixel = bm.bmBitsPixel * bm.bmPlanes;if (iBitsPixel < 24)return -1;// 位图信息头结构 BITMAPINFOHEADER bmih = { 0 };bmih.biSize = sizeof(bmih);bmih.biWidth = bm.bmWidth;bmih.biHeight = bm.bmHeight;bmih.biPlanes = 1;bmih.biBitCount = iBitsPixel;bmih.biCompression = BI_RGB;bmih.biSizeImage = 0;bmih.biXPelsPerMeter = 0;bmih.biYPelsPerMeter = 0;bmih.biClrUsed = 0;bmih.biClrImportant = 0;// 调色板DWORD dwPaletteSize = 0;// 创建DIB位图内容DWORD dwSize = ((bm.bmWidth * iBitsPixel + 31) / 32) * 4 * bm.bmHeight;DWORD dwDIBSize = sizeof(BITMAPINFOHEADER) + dwPaletteSize + dwSize;LPVOID lpDIB = ::HeapAlloc(::GetProcessHeap(), HEAP_ZERO_MEMORY, dwDIBSize);LPBITMAPINFOHEADER lpbmih = (LPBITMAPINFOHEADER)lpDIB;*lpbmih = bmih;::GetDIBits(hdc, hBitmap, 0, bm.bmHeight, (char*)lpDIB + sizeof(BITMAPINFOHEADER) + dwPaletteSize,(PBITMAPINFO)lpbmih, DIB_RGB_COLORS);// 位图文件头BITMAPFILEHEADER bmfh;bmfh.bfType = 0x4d42;bmfh.bfSize = sizeof(BITMAPFILEHEADER) + dwDIBSize;bmfh.bfReserved1 = 0;bmfh.bfReserved2 = 0;bmfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + dwPaletteSize;// 创建.bmp文件并保存HANDLE hFile = ::CreateFile(name,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);if (INVALID_HANDLE_VALUE == hFile)return GetLastError();DWORD dwWritten = 0;::WriteFile(hFile, &bmfh, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);::WriteFile(hFile, lpDIB, dwDIBSize, &dwWritten, NULL);::HeapFree(::GetProcessHeap(), 0, lpDIB);::CloseHandle(hFile);return 0;}int main(){HDC hdcScreen = ::CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);HBITMAP hBitmapScreen = CaptureScreenToDDB();if (hBitmapScreen == NULL){cout << "CaptureScreenToDDB() failed." << endl;return -1;}TCHAR name[] = TEXT("d:\\1234.bmp");cout << SaveDDBToFile(hBitmapScreen, hdcScreen, name) << endl;cout << "Hello Kitty" << endl;system("pause");}