How to get random number within a range using C++ - 如何用C++获取一定范围内的随机数

void CprjGetRandomNumberWithinRangeDlg::OnBnClickedbtntest()
{
	// TODO: Add your control notification handler code here
	int i;
	long lRandom;
	CString strMsg;
	//===========================================================================================
	for(i = 0;i < 100;i++)
	{
		GetRandomNumberWithinRange(lRandom,strMsg);
		TRACE(_T("%d/r/n"),lRandom);
	}
	
}

//Defination : 
//bool GetRandomNumberWithinRange(long & lRandom, CString & strMsg, long lNumberMin = 1, long lNumberMax = 19);
bool CprjGetRandomNumberWithinRangeDlg::GetRandomNumberWithinRange(long & lRandom, CString & strMsg, long lNumberMin, long lNumberMax)
{
	if(lNumberMax < lNumberMin)
	{
		strMsg = _T("lNumberMax can't be less than lNumberMin");
		return false;
	}

	//随机数范围 : 5 到 20(5 + (16 - 1)) 范围
	lRandom = rand() % (lNumberMax - lNumberMin + 1) + lNumberMin;
	
	return true;
}