Win32显示系统调用失败后的错误信息

DWORD ShowSystemError(HWND hwndMsgOwner)
{
	DWORD dwError = GetLastError();
	HLOCAL hlocal = NULL;
	FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_ALLOCATE_BUFFER,
		NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL), (PTSTR)&hlocal, 0, NULL);
	MessageBox(hwndMsgOwner, (TCHAR*)LocalLock(hlocal), 0, 0);
	LocalFree(hlocal);
	return dwError;
}

void ShowSystemError(HWND hwndMsgOwner, DWORD dwError)
{
	HLOCAL hlocal = NULL;
	FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_ALLOCATE_BUFFER,
		NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL), (PTSTR)&hlocal, 0, NULL);
	MessageBox(hwndMsgOwner, (TCHAR*)LocalLock(hlocal), 0, 0);
	LocalFree(hlocal);
}