//是否16进制，只包括0-9和小数点和ABCDEF

bool CSFCApp::IsHex(CString str)
{

int iLen = str.GetLength();
bool bHex = true;
for(int i=0; i<iLen; i++)
{
if ((str[i] >= ‘0‘ && str[i] <= ‘9‘)
|| (str[i] >= ‘A‘ && str[i] <= ‘F‘)
|| (str[i] >= ‘a‘ && str[i] <= ‘f‘)
|| str[i] == ‘.‘)
{
bHex = true;
}
else
{
bHex = false;
return false;
}
}
return bHex;
}

原文：https://www.cnblogs.com/ShiShouTHS/p/11365159.html