ios设置导航栏背景图片、返回按钮背景、标题颜色等等

    在ios程序的编写过程中，很多时候我们都要自定义自己的UI，而不是使用cocoatouch中原有的。说起对UI的更改，很多时候我们只是修改一下原有UI的背景啊，颜色之类的，以达到新的要求。
    在此之前呢，设置UINavigationController的背景颜色，我会使用如下的代码：
首先看.h文件

#import <UIKit/UIKit.h>@interface UINavigationBar (CustomBar)- (void)customNavigationBar;@end

.m文件

#import "UINavigationBar+CustomBar.h"#import <QuartzCore/QuartzCore.h>@implementation UINavigationBar (CustomBar)- (void)customNavigationBar{    if ([self respondsToSelector:@selector(setBackgroundImage:forBarMetrics:)])    {        CGSize titleSize = self.bounds.size;  //获取Navigation Bar的位置和大小        UIImage *image = [UIImage imageNamed:@"img_nav_backimg"];                UIGraphicsBeginImageContext(titleSize);        [image drawInRect:CGRectMake(0, 0, titleSize.width, titleSize.height)];        UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();        UIGraphicsEndImageContext();        [self setBackgroundImage:scaledImage forBarMetrics:UIBarMetricsDefault];    }    else    {        [self drawRect:self.bounds];    }    //    [self drawRoundCornerAndShadow];}- (void)drawRect:(CGRect)rect {    [[UIImage imageNamed:@"img_nav_backimg.png"] drawInRect:rect];}- (void)drawRoundCornerAndShadow {    CGRect bounds = self.bounds;    bounds.size.height +=10;    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:bounds                                                   byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight)                                                         cornerRadii:CGSizeMake(10.0, 10.0)];        CAShapeLayer *maskLayer = [CAShapeLayer layer];    maskLayer.frame = bounds;    maskLayer.path = maskPath.CGPath;        [self.layer addSublayer:maskLayer];    self.layer.mask = maskLayer;    self.layer.shadowOffset = CGSizeMake(3, 3);    self.layer.shadowOpacity = 0.7;    self.layer.shadowPath = [UIBezierPath bezierPathWithRect:self.bounds].CGPath;}@end

调用时如下：

//设置导航栏底图+ (void)setNavigationCtrollerBackImg:(UINavigationController *)naviCtl{    [naviCtl.navigationBar customNavigationBar];}

    这样的写法是一个不错的选择。如果说要修改 self.title的颜色呢，相信很多人都会想到自定义UILabel，然后self.navigationControl.titleView = Label，这针对几个页面也许是一个比较不错的选择，可是如果很多页面，甚至所有的页面都需要呢，你或许会说设置一个基础类，然
后从这个基础类继承过来，这也可以，但是不是最简便的方式。
    好了，说了这么多，我们来看看我最近看到的一个比较方便的方法吧：

#pragma mark 初始化导航栏主题- (void)setNavTheme{    // 1.设置导航栏背景    UINavigationBar *bar = [UINavigationBar appearance];    [bar setBackgroundImage:[UIImage resizeImage:@"NavigationBar_Background.png"] forBarMetrics:UIBarMetricsDefault];    // 状态栏    [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleBlackOpaque;        // 2.设置导航栏文字属性    NSMutableDictionary *barAttrs = [NSMutableDictionary dictionary];    [barAttrs setObject:[UIColor darkGrayColor] forKey:UITextAttributeTextColor];    [barAttrs setObject:[NSValue valueWithUIOffset:UIOffsetMake(0, 0)] forKey:UITextAttributeTextShadowOffset];    [bar setTitleTextAttributes:barAttrs];        // 3.按钮    UIBarButtonItem *item = [UIBarButtonItem appearance];    [item setBackgroundImage:[UIImage resizeImage:@"BarButtonItem_Normal.png"] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];    [item setBackgroundImage:[UIImage resizeImage:@"BarButtonItem_Pressed.png"] forState:UIControlStateHighlighted barMetrics:UIBarMetricsDefault];        NSMutableDictionary *itemAttrs = [NSMutableDictionary dictionaryWithDictionary:barAttrs];    [itemAttrs setObject:[UIFont boldSystemFontOfSize:13] forKey:UITextAttributeFont];    [item setTitleTextAttributes:itemAttrs forState:UIControlStateNormal];    [item setTitleTextAttributes:itemAttrs forState:UIControlStateHighlighted];    [item setTitleTextAttributes:itemAttrs forState:UIControlStateDisabled];        // 4.返回按钮    [item setBackButtonBackgroundImage:[UIImage resizeImage:@"BarButtonItem_Back_Normal.png"] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];    [item setBackButtonBackgroundImage:[UIImage resizeImage:@"BarButtonItem_Back_Pressed.png"] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];        //返回按钮的标题    UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] init];    barButtonItem.title = @"buttonName";    self.navigationItem.backBarButtonItem = barButtonItem;     [barButtonItem release]}

    这个方法极大的减轻了自定义带来的代码开销，用在换肤方面可能会更好的体现。是不是很不错啊！