All she's complaining about is not that she gets hit on, but that she keeps getting hit on in the wrong way. She gives her contact details out to men whom she thinks want to be business contacts, who then wind up calling her for dates.

It's a simple rule: if you meet a woman and you're interested in her in that way, then hit on her properly and ask her for her number in a way that makes your intentions non-ambiguous. If you're interested in her professionally then by all means exchange business cards. If you're interested in her in both ways then... well, choose one.