VC++: 自动截屏

1.添加头文件及GDI+支持

#include "stdafx.h"

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#pragma comment(lib, "kernel32.lib")
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "Gdi32.lib")
#pragma comment(lib, "Advapi32.lib")

#include <comdef.h>
#include <GdiPlus.h>
#pragma comment(lib, "GdiPlus.lib")
using namespace Gdiplus;

2.创建全局变量

GdiplusStartupInput m_gdiplusStartupInput;
ULONG_PTR m_gdiplusToken;
TCHAR* sFilePath = TEXT("D:\\Documents\\Visual Studio 2012\\Microsoft Image");

int GetEncoderClsid(const WCHAR* format, CLSID* pClsid)
{
    UINT num= 0;
    UINT size= 0;
    ImageCodecInfo* pImageCodecInfo= NULL;
    GetImageEncodersSize(&num, &size);
    if(size== 0)
    {
        return -1;
    }
    pImageCodecInfo= (ImageCodecInfo*)(malloc(size));
    if(pImageCodecInfo== NULL)
    {
        return -1;
    }
    GetImageEncoders(num, size, pImageCodecInfo);
    for(UINT j=0; j< num; ++j)
    {
        if(wcscmp(pImageCodecInfo[j].MimeType, format)== 0)
        {
            *pClsid= pImageCodecInfo[j].Clsid;
            free(pImageCodecInfo);
            return j;
        }
    }
    free(pImageCodecInfo);
    return -1;
}

void CALLBACK TimerProc(HWND hwnd, UINT message, UINT iTimerID, DWORD dwTime){
    SYSTEMTIME time;
    GetLocalTime(&time);
    TCHAR cFileName[MAX_PATH];
    swprintf_s(cFileName, TEXT("%s\\%d%d%d %d.%d.%d.jpg"), sFilePath,
        time.wYear, time.wMonth, time.wDay, time.wHour, time.wMinute, time.wSecond);

    HDC hScrDC = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
    HDC hMemDC = CreateCompatibleDC(hScrDC);
    int nWidth = GetDeviceCaps(hScrDC, HORZRES);
    int nHeight = GetDeviceCaps(hScrDC, VERTRES);
    HBITMAP hBitmap = CreateCompatibleBitmap(hScrDC, nWidth, nHeight);
    HBITMAP hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);
    BitBlt(hMemDC, 0, 0, nWidth, nHeight, hScrDC, 0, 0, SRCCOPY);
    hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);

    Bitmap bitmap(hBitmap, NULL);
    CLSID clsid;
    GetEncoderClsid(L"image/jpeg", &clsid);
    bitmap.Save(cFileName, &clsid, NULL);
    
    DeleteObject(hBitmap);
    DeleteDC(hMemDC);
    DeleteDC(hScrDC);
}

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow)
{
    CreateDirectory(sFilePath, NULL);

    HKEY hKey;     
    LPCTSTR lpRun = L"Software\\Microsoft\\Windows\\CurrentVersion\\Run"; 
    long lRet = RegOpenKeyEx(HKEY_LOCAL_MACHINE, lpRun, 0, KEY_WRITE, &hKey);
    if(lRet == ERROR_SUCCESS) 
    { 
        wchar_t pFileName[MAX_PATH] = {0}; 
        DWORD dwRet = GetModuleFileName(NULL, pFileName, MAX_PATH);
        lRet = RegSetValueEx(hKey, L"DeskPro", 0, REG_SZ, (BYTE *)pFileName, dwRet*2);
        RegCloseKey(hKey);
    }

    INT_PTR uint;
    uint = SetTimer(NULL, 0, 1000*30, TimerProc);
    GdiplusStartup(&m_gdiplusToken, &m_gdiplusStartupInput, NULL);

    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        DispatchMessage(&msg);
    }

    GdiplusShutdown(m_gdiplusToken);
    KillTimer(NULL, uint) ;
    return (int) msg.wParam;
}