#include <windows.h>
int main(int argc, char *argv[])
{
  HWND hWnd = ::GetForegroundWindow();
  ::SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 100, 100, SWP_NOMOVE | SWP_NOSIZE);
  return FALSE;
}

#include <windows.h>
// windows置顶窗体终极方案
BOOL OnForceShow(HWND hWnd)
{
  HWND hForeWnd = NULL;
  DWORD dwForeID = 0;
  DWORD dwCurID = 0;
  hForeWnd = ::GetForegroundWindow();
  dwCurID = ::GetCurrentThreadId();
  dwForeID = ::GetWindowThreadProcessId(hForeWnd, NULL);
  ::AttachThreadInput(dwCurID, dwForeID, TRUE);
  ::ShowWindow(hWnd, SW_SHOWNORMAL);
  ::SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE);
  ::SetWindowPos(hWnd, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE);
  ::SetForegroundWindow(hWnd);
  // 将前台窗口线程贴附到当前线程（也就是程序A中的调用线程）
  ::AttachThreadInput(dwCurID, dwForeID, FALSE);
  return TRUE;
}
int main(int argc, char *argv[])
{
  HWND hWnd = ::GetForegroundWindow();
  if (OnForceShow(hWnd))
    return TRUE;
  ::SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 100, 100, SWP_NOMOVE | SWP_NOSIZE);
  return FALSE;
}