导航栏底部添加阴影

//
// UINavigationBar+JTDropShadow.h
//
// Created by james on 9/20/11.
// http://ioscodesnippet.tumblr.com
//


#import

@interface UINavigationBar (JTDropShadow)

- (void)dropShadowWithOffset:(CGSize)offset
radius:(CGFloat)radius
color:(UIColor *)color
opacity:(CGFloat)opacity;


@end




//
// UINavigationBar+JTDropShadow.m
//
// Created by james on 9/20/11.
// http://ioscodesnippet.tumblr.com
//


#import "UINavigationBar+JTDropShadow.h"

#import



@implementation UINavigationBar (JTDropShadow)

- (void)dropShadowWithOffset:(CGSize)offset
radius:(CGFloat)radius
color:(UIColor *)color
opacity:(CGFloat)opacity {

// Creating shadow path for better performance
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddRect(path, NULL, self.bounds);
self.layer.shadowPath = path;
CGPathCloseSubpath(path);
CGPathRelease(path);

self.layer.shadowColor = color.CGColor;
self.layer.shadowOffset = offset;
self.layer.shadowRadius = radius;
self.layer.shadowOpacity = opacity;

// Default clipsToBounds is YES, will clip off the shadow, so we disable it.
self.clipsToBounds = NO;

}

@end


//用法如下

- (void)viewDidLoad {
[super viewDidLoad];
...
[self.navigationController.navigationBar dropShadowWithOffset:CGSizeMake(0, 3)
radius:1
color:[UIColor darkGrayColor]
opacity:1];
...
}