捕捉屏幕和光标

另外使用createfile函数将捕捉后的图片储存为文件

#include <Windows.h>
#include <stdio.h>
#include <assert.h>

void scrshot() {
    Sleep(1000);
    BITMAP bmpScreen;
    HWND hwnd = GetDesktopWindow();
    HDC hdc = GetWindowDC(hwnd);
    HDC hdcMem = CreateCompatibleDC(hdc);
    int cx = GetDeviceCaps(hdc, HORZRES);
    int cy = GetDeviceCaps(hdc, VERTRES);
    HBITMAP hbitmap(NULL);
    hbitmap = CreateCompatibleBitmap(hdc, cx, cy);
    SelectObject(hdcMem, hbitmap);
    BitBlt(hdcMem, 0, 0, cx, cy, hdc, 0, 0, SRCCOPY);
    CURSORINFO cursor = { sizeof(cursor) };
    GetCursorInfo(&cursor);
    if (cursor.flags == CURSOR_SHOWING) {
        RECT rect;
        GetWindowRect(hwnd, &rect);
        ICONINFO info = { sizeof(info) };
        GetIconInfo(cursor.hCursor, &info);
        const int x = cursor.ptScreenPos.x - rect.left - rect.left - info.xHotspot;
        const int y = cursor.ptScreenPos.y - rect.top - rect.top - info.yHotspot;
        BITMAP bmpCursor = { 0 };
        GetObject(info.hbmColor, sizeof(bmpCursor), &bmpCursor);
        DrawIconEx(hdcMem, x, y, cursor.hCursor, bmpCursor.bmWidth, bmpCursor.bmHeight,
            0, NULL, DI_NORMAL);


        GetObject(hbitmap, sizeof(BITMAP), &bmpScreen);

        BITMAPFILEHEADER   bmfHeader;
        BITMAPINFOHEADER   bi;

        bi.biSize = sizeof(BITMAPINFOHEADER);
        bi.biWidth = bmpScreen.bmWidth;
        bi.biHeight = bmpScreen.bmHeight;
        bi.biPlanes = 1;
        bi.biBitCount = 24;
        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;    //位图大小

        // 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);


        //GetDIBits函数检索指定兼容位图的位，
        //并使用指定的格式将其作为dib复制到缓冲区中。
        GetDIBits(hdc, hbitmap, 0,
            (UINT)bmpScreen.bmHeight,
            lpbitmap,    //指向接收位图数据的缓冲区的指针。如果此参数为空，则函数将位图的尺寸和格式传递给lpbi参数指向的bitmapinfo结构。 
            (BITMAPINFO *)&bi, //指向指定DIB数据所需格式的BitmapInfo结构的指针
            DIB_RGB_COLORS);

        // A file is created, this is where we will save the screen capture.
        HANDLE hFile = CreateFile("captureqwsx1.bmp",
            GENERIC_WRITE,
            0,
            NULL,
            CREATE_ALWAYS,
            FILE_ATTRIBUTE_NORMAL, NULL);

        // 将headers的大小添加到位图的大小中, 以获取总文件大小
        DWORD dwSizeofDIB = dwBmpSize + sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

        //偏移到实际位图位开始的位置。
        bmfHeader.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER);

        //Size of the file
        bmfHeader.bfSize = dwSizeofDIB;

        //bfType must always be BM for Bitmaps
        bmfHeader.bfType = 0x4D42; //BM   

        DWORD dwBytesWritten = 0;
        WriteFile(hFile, (LPSTR)&bmfHeader, sizeof(BITMAPFILEHEADER), &dwBytesWritten, NULL);
        WriteFile(hFile, (LPSTR)&bi, sizeof(BITMAPINFOHEADER), &dwBytesWritten, NULL);
        WriteFile(hFile, (LPSTR)lpbitmap, dwBmpSize, &dwBytesWritten, NULL);


    }
}

int main() {
    scrshot();
    return 0;
}