1、導航欄下方橫線隱藏或其他顯示效果。

UIImageView *navBarHairlineImageView = [self findHairlineImageViewUnder:self.navigationController.navigationBar];
navBarHairlineImageView.hidden = YES;
- (UIImageView *)findHairlineImageViewUnder:(UIView *)view {
    if ([view isKindOfClass:UIImageView.class] && view.bounds.size.height <= 1.0) {
        return (UIImageView *)view;
    }
    for (UIView *subview in view.subviews) {
        UIImageView *imageView = [self findHairlineImageViewUnder:subview];
        if (imageView) {
            return imageView;
        }
    }
    return nil;
}
 

2、導航欄背景顏色。

self.navigationController.navigationBar.barTintColor = [UIColor whiteColor];

3、導航欄是否透明。

self.navigationController.navigationBar.translucent = NO;

4、導航欄標題顏色。

[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];

5、導航欄隱藏。

self.navigationController.navigationBarHidden = YES;