We have known each other for half a year. Once I invited her to dinner, she gave me a gift and ignored me. What should I do if I don't answer the SMS or QQ or the phone?

Hello, girls are generally reserved. If you usually get along well, she doesn't reply to your message and says she needs to think about it. You still have hope. At this stage, you need to let him know you better. If you are of good quality, you still have a good chance of being together. You shouldn't deal with emotional problems in a hurry. I hope my answer will satisfy you.