If I got a gift card when I withdrew my money and I took a screenshot of the barcode can I send it with my boy friend and it work at the store or does it have to be off my phone?
Gift cards are just like the ones you buy at any store. You can send the screenshot (and PIN if applicable) to anyone and they can use it.
Also realize, if anyone uses your phone, they could get the same information and use it. Consider gift cards the same as cash. Keep it safe.