显示GetLastError函数的错误信息

void ShowErrMsg()
{
      TCHAR szBuf[80];
      LPVOID lpMsgBuf;
      DWORD dw = GetLastError();

      FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER    | FORMAT_MESSAGE_FROM_SYSTEM,NULL,dw,MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),(LPTSTR) &lpMsgBuf,0, NULL );

      MessageBox(NULL, (LPCTSTR)lpMsgBuf, "系统错误", MB_OK|MB_ICONSTOP);

      LocalFree(lpMsgBuf);
}