把segmentControl边框隐藏

segment.tintColor = [UIColor clearColor];//去掉颜色,现在整个segment都看不见

    NSDictionary* selectedTextAttributes = @{NSFontAttributeName:[UIFont boldSystemFontOfSize:16],
                            NSForegroundColorAttributeName: [UIColor whiteColor]};
    [segment setTitleTextAttributes:selectedTextAttributes forState:UIControlStateSelected];//设置文字属性
NSDictionary* unselectedTextAttributes = @{NSFontAttributeName:[UIFont boldSystemFontOfSize:16],
                                 NSForegroundColorAttributeName: [UIColor lightTextColor]};
[segment setTitleTextAttributes:unselectedTextAttributes forState:UIControlStateNormal];