Trust me,first, my code are copied from the tutorial of the official site, so there's definitely no problem of the code, secondly, i am able to get other key events, like any letters, numbers, escape. but it's strange when i press + or - (which are represented by sf::Key::Subtract and sf::Key::Add),nothing happens? anyone met the same problem?
(probem solved, it's a keyboard layout problem, thanks for your ans...i don't know why but i can't post reply here, so i answer you from here)