UIButton根据状态不同设置不同的背景图

- (void)handleSelect:(UIButton *)sender{

    UIButton *btn = (UIButton *)sender;

    btn.selected = !btn.selected;

    if (btn.selected) {

        [btn setBackgroundImage:[UIImage imageNamed:@"selected"] forState:UIControlStateSelected];

//        btn.selected = NO;

    }else {

        [btn setBackgroundImage:[UIImage imageNamed:@"unselected"] forState:UIControlStateNormal];

//        btn.selected = YES;

    }

}