Win32截屏

来源：互联网发布：中国科研现状知乎编辑：程序博客网时间：2024/06/17 11:39
/* 头文件 */#include <windows.h>/* 常量定义 */#define PALVERSION 0x300#define CAP_SHOW_MODE_STRTCH 1#define CAP_SHOW_MODE_NOSTRTCH 0/* 全局变量 */HBITMAP ghBitmap = NULL;RECT rectShow;// 修改这里截取不同的窗口，如果为NULL，则截取屏幕LPSTR szCaptureWindowName = "任务管理器";/* 函数申明 */LRESULT CALLBACK MainWndProc(HWND, UINT, WPARAM, LPARAM);HBITMAP ScreenCapture(LPSTR filename, WORD BitCount, LPRECT lpRect);VOID DoPaint(HWND hWnd, DWORD dwMode);/************************************** DWORD WINAPI WinMain(HINSTANCE hinstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow)* 功能 截屏，保存为文件，并显示在窗口上***************************************/INT WINAPI WinMain(HINSTANCE hinstance,    HINSTANCE hPrevInstance,    LPSTR lpCmdLine,    int nCmdShow){    WNDCLASSEX wcx;    HWND hwnd;    MSG msg;    WORD wport = 80;    BOOL fGotMessage;    HWND hwndCap = NULL;    // 截取全屏幕还是窗口    if (szCaptureWindowName != NULL)    {        hwndCap = FindWindow(NULL, "任务管理器");        // 获取窗口的RECT，可自行修改，获取屏幕中的任意区域        if (!GetWindowRect(hwndCap, &rectShow))        {            MessageBox(NULL, "Can not find window to capture", "erroe", MB_OK);            return 0;        }    }    // 注册窗口类，并创建窗口，用于显示截取的位图    wcx.cbSize = sizeof(wcx);    wcx.style = CS_HREDRAW | CS_VREDRAW;    wcx.lpfnWndProc = MainWndProc;    wcx.cbClsExtra = 0;    wcx.cbWndExtra = 0;    wcx.hInstance = hinstance;    wcx.hIcon = LoadIcon(NULL, MAKEINTRESOURCE(IDI_APPLICATION));    wcx.hCursor = LoadCursor(NULL, IDC_ARROW);    wcx.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);    wcx.lpszMenuName = NULL;    wcx.lpszClassName = "MainWClass";    wcx.hIconSm = NULL;    if (!RegisterClassEx(&wcx))        return 1;    // 创建窗口    hwnd = CreateWindow(        "MainWClass",        "CAP",        WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN | WS_CLIPSIBLINGS |        WS_MAXIMIZE | WS_POPUPWINDOW,        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,        (HWND)NULL, (HMENU)NULL, hinstance, (LPVOID)NULL);    if (!hwnd)        return 1;    // 截取屏幕，可根据需要设置不同的参数，这里只演示截取特定窗口。    ghBitmap = ScreenCapture("taskmgr.bmp", 32, &rectShow);    // 显示    ShowWindow(hwnd, nCmdShow);    UpdateWindow(hwnd);    while ((fGotMessage = GetMessage(&msg, (HWND)NULL, 0, 0)) != 0 && fGotMessage != -1)    {        TranslateMessage(&msg);        DispatchMessage(&msg);    }    return msg.wParam;    UNREFERENCED_PARAMETER(lpCmdLine);}LRESULT CALLBACK MainWndProc(    HWND hwnd,    UINT uMsg,    WPARAM wParam,    LPARAM lParam){    switch (uMsg)    {    case WM_PAINT:        // 显示截取的屏幕        DoPaint(hwnd, CAP_SHOW_MODE_STRTCH);        break;    case WM_DESTROY:        // 创建的BITMAP对象需要删除，以释放资源        DeleteObject(ghBitmap);        ExitProcess(0);        break;    default:        break;    }    return DefWindowProc(hwnd, uMsg, wParam, lParam);}/************************************** VOID DoPaint(HWND hWnd, DWORD dwMode)* 功能 将位图（全局变量ghBitmap）显示在界面上** 参数 HWND hWnd，用于显示位图的窗口* DWORD dwMode，模式，是否拉申** 无返回值**************************************/VOID DoPaint(HWND hWnd, DWORD dwMode){    PAINTSTRUCT ps;    RECT rect;    HDC hdcMem;    BITMAP bm;    // BeginPaint    HDC hDC = BeginPaint(hWnd, &ps);    // 获取窗口的Client区域，用于显示位图    GetClientRect(hWnd, &rect);    // 设置拉申模式    SetStretchBltMode(hDC, HALFTONE);    // 将BITMAP对象选择入内存DC    hdcMem = CreateCompatibleDC(hDC);    SelectObject(hdcMem, ghBitmap);    if (ghBitmap)    {        // 获取DIB属性        if (GetObject(ghBitmap, sizeof(BITMAP), &bm))        {            // 判断参数示：是否根据显示窗口大小拉申位图            // 采用不同的方面将内存DC StretchBl t至窗口Client区域DC            if (dwMode == CAP_SHOW_MODE_STRTCH)            {                StretchBlt(hDC, 0, 0, rect.right, rect.bottom,                    hdcMem, 0, 0, bm.bmWidth, bm.bmHeight, SRCCOPY);            }            else            {                // 不拉伸，计算显示的位置，将其显示在Client的中央                INT ixStart = (rect.right - rect.left - bm.bmWidth) / 2;                INT iyStart = (rect.bottom - rect.top - bm.bmHeight) / 2;                ixStart = ixStart < 0 ? 0 : ixStart;                iyStart = iyStart < 0 ? 0 : iyStart;                BitBlt(hDC, 0, 0, rect.right, rect.bottom,                    hdcMem, -ixStart, -iyStart, SRCCOPY);            }            DeleteDC(hdcMem);        }    }    // 如果没有位图，则使用Brush填充    else    {        PatBlt(hDC, 0, 0, rect.right, rect.bottom, BLACKNESS);    }    // EndPaint    EndPaint(hWnd, &ps);}/************************************** BITMAP ScreenCapture(LPSTR filename ,WORD BitCount,LPRECT lpRect);* 功能 截取指定区域的屏幕，并保存为文件** 参数    LPSTR filename 保存位图文件的文件路径，如果为NULL，则不保存*       WORD BitCount Bit深度，用于表示一个像素点所使用的数据长度*       LPRECT lpRect 所需截取的屏幕区域，如果为NULL，则获取全屏幕** 返回 HBITMAP 所截取的位图对象**************************************/HBITMAP ScreenCapture(LPSTR filename, WORD BitCount, LPRECT lpRect){    HBITMAP hBitmap;    // 显示器屏幕DC    HDC hScreenDC = CreateDC("DISPLAY", NULL, NULL, NULL);    HDC hmemDC = CreateCompatibleDC(hScreenDC);    // 显示器屏幕的宽和高    int ScreenWidth = GetDeviceCaps(hScreenDC, HORZRES);    int ScreenHeight = GetDeviceCaps(hScreenDC, VERTRES);    // 旧的BITMAP，用于与所需截取的位置交换    HBITMAP hOldBM;    // 保存位图数据    PVOID lpvpxldata;    // 截屏获取的长宽及起点    INT ixStart;    INT iyStart;    INT iX;    INT iY;    // 位图数据大小    DWORD dwBitmapArraySize;    // 几个大小    DWORD nBitsOffset;    DWORD lImageSize;    DWORD lFileSize;    // 位图信息头    BITMAPINFO bmInfo;    // 位图文件头    BITMAPFILEHEADER bmFileHeader;    // 写文件用    HANDLE hbmfile;    DWORD dwWritten;    // 如果LPRECT 为NULL 截取整个屏幕    if (lpRect == NULL)    {        ixStart = iyStart = 0;        iX = ScreenWidth;        iY = ScreenHeight;    }    else    {        ixStart = lpRect->left;        iyStart = lpRect->top;        iX = lpRect->right - lpRect->left;        iY = lpRect->bottom - lpRect->top;    }    // 创建BTIMAP    hBitmap = CreateCompatibleBitmap(hScreenDC, iX, iY);    // 将BITMAP选择入内存DC。    hOldBM = (HBITMAP)SelectObject(hmemDC, hBitmap);    // BitBlt屏幕DC到内存DC，根据所需截取的获取设置参数    BitBlt(hmemDC, 0, 0, iX, iY, hScreenDC, ixStart, iyStart, SRCCOPY);    // 将旧的BITMAP对象选择回内存DC，返回值为被替换的对象，既所截取的位图    hBitmap = (HBITMAP)SelectObject(hmemDC, hOldBM);    if (filename == NULL)    {        DeleteDC(hScreenDC);        DeleteDC(hmemDC);        return hBitmap;    }    // 为位图数据申请内存空间    dwBitmapArraySize = ((((iX * 32) + 31) & ~31) >> 3)* iY;    lpvpxldata = HeapAlloc(GetProcessHeap(), HEAP_NO_SERIALIZE, dwBitmapArraySize);    ZeroMemory(lpvpxldata, dwBitmapArraySize);    // 添充 BITMAPINFO 结构    ZeroMemory(&bmInfo, sizeof(BITMAPINFO));    bmInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);    bmInfo.bmiHeader.biWidth = iX;    bmInfo.bmiHeader.biHeight = iY;    bmInfo.bmiHeader.biPlanes = 1;    bmInfo.bmiHeader.biBitCount = BitCount;    bmInfo.bmiHeader.biCompression = BI_RGB;    // 添充 BITMAPFILEHEADER 结构    ZeroMemory(&bmFileHeader, sizeof(BITMAPFILEHEADER));    nBitsOffset = sizeof(BITMAPFILEHEADER) + bmInfo.bmiHeader.biSize;    lImageSize =        ((((bmInfo.bmiHeader.biWidth * bmInfo.bmiHeader.biBitCount) + 31) & ~31) >> 3)        * bmInfo.bmiHeader.biHeight;    lFileSize = nBitsOffset + lImageSize;    bmFileHeader.bfType = 'B' + ('M' << 8);    bmFileHeader.bfSize = lFileSize;    bmFileHeader.bfOffBits = nBitsOffset;    // 获取DIB用于写入到文件    GetDIBits(hmemDC, hBitmap, 0, bmInfo.bmiHeader.biHeight,        lpvpxldata, &bmInfo, DIB_RGB_COLORS);    // 写文件    hbmfile = CreateFile(filename,        GENERIC_WRITE,        FILE_SHARE_WRITE,        NULL,        CREATE_ALWAYS,        FILE_ATTRIBUTE_NORMAL,        NULL);    if (hbmfile == INVALID_HANDLE_VALUE)    {        MessageBox(NULL, "create file error", "error", MB_OK);    }    WriteFile(hbmfile, &bmFileHeader, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);    WriteFile(hbmfile, &bmInfo, sizeof(BITMAPINFO), &dwWritten, NULL);    WriteFile(hbmfile, lpvpxldata, lImageSize, &dwWritten, NULL);    CloseHandle(hbmfile);    // 释放内存，清除不同的DC。    // 这里没有删除BITMAP对象，需在显示完成后删除    HeapFree(GetProcessHeap(), HEAP_NO_SERIALIZE, lpvpxldata);    ReleaseDC(0, hScreenDC);    DeleteDC(hmemDC);    return hBitmap;}
转载：http://blog.csdn.net/itcastcpp/article/details/7079602
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