Purpose

It is hard to change the appearance of UINavigationBar dynamically, so I made this lib to make the job easy.

Demo

1. Changing the background color:

2. Making navigation bar scroll along with a scroll view:

Usage

First, import this lib:

#import "UINavigationBar+Awesome.h"

The category includes lots of method that helps to change UINavigationBar's appearance dynamically:

@interface UINavigationBar (Awesome)
- (void)lt_setBackgroundColor:(UIColor *)backgroundColor;
- (void)lt_setElementsAlpha:(CGFloat)alpha;
- (void)lt_setTranslationY:(CGFloat)translationY;
- (void)lt_reset;
@end

You can call the various setter wherever you want, like:

[self.navigationController.navigationBar lt_setBackgroundColor:[UIColor blueColor]];

And usually in viewWillDisappear, you should call this method to avoid any side effects:

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [self.navigationController.navigationBar lt_reset];
}

See the example for details~