定制导航栏

想定制导航栏吗？从iOS5开始你就可以改变导航栏的背景图片、tintcolor或者标题文本。

这里我们将介绍如何在Xcode中定制导航栏。

 

从这里你可以下载到本文用到的按钮： Buttons.zip

首先需要获取UINavigationController引用。你可以在创建UINavigationController时定制导航栏，也可以在ViewController加载到UINavigationController时定制导航栏。

打开要引用UINavigationController的类，在viewDidLoad方法中定制导航栏的背景图片，如下列代码所示：

 

UIImage *navbarPortrait= [[UIImageimageNamed:@"navbar_44.png"]                               

 resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];     

UIImage *navbarLandscape =[[UIImage imageNamed:@"navbar_32.png"]                                

resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];      

// Setbackgroundimage for all navigationcontrollers     

[[UINavigationBar appearance] setBackgroundImage:navbarPortrait                                        

forBarMetrics:UIBarMetricsDefault];    

[[UINavigationBarappearance] setBackgroundImage:navbarLandscape                                       

 forBarMetrics:UIBarMetricsLandscapePhone];

 

 

导航栏的背景图片必须是下列高度：

竖屏：44px(retina 屏则为 88px)
横屏：32px (retina 屏则为 64px)

 

BarButton（包括backButton）的背景图片用backgroundimage属性设置。BarButton的背景图片必须是下列高度：

竖屏：30px(retina 屏则为 60px)
横屏：24px(retina 屏则为 48px)

 

如果标题文本过长（超过按钮图片的宽度）图片将被缩放。

   

// Setbackgroundimage for all buttons    

UIImage *buttonPortait= [[UIImageimageNamed:@"button_30.png"]                               

resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];     

UIImage *buttonLandscape =[[UIImage imageNamed:@"button_24.png"]                                 

resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];     

[[UIBarButtonItem appearance] setBackgroundImage:buttonPortait                                             

forState:UIControlStateNormal                                            

barMetrics:UIBarMetricsDefault];    

[[UIBarButtonItemappearance] setBackgroundImage:buttonLandscape                                             

forState:UIControlStateNormal                                           

barMetrics:UIBarMetricsLandscapePhone];    

// Setbackgroundimage for all backbuttons    

UIImage *backButtonPortait= [[UIImageimageNamed:@"back_button_30.png"]                                  

 resizableImageWithCapInsets:UIEdgeInsetsMake(0, 13, 0, 5)];     

UIImage *backButtonLandscape =[[UIImage imageNamed:@"back_button_24.png"]                                    

 resizableImageWithCapInsets:UIEdgeInsetsMake(0, 10, 0, 4)];    

[[UIBarButtonItem appearance]setBackButtonBackgroundImage:backButtonPortait                                                      

 forState:UIControlStateNormal                                                     

barMetrics:UIBarMetricsDefault];    

[[UIBarButtonItemappearance]setBackButtonBackgroundImage:backButtonLandscape                                                      

forState:UIControlStateNormal                                                     

barMetrics:UIBarMetricsLandscapePhone];

 

还可以通过titleTextAttriutes属性定制UIBarButton。setTitleTextAttributes:方法用一个NSDictionary参数指定所需选项：

UITextAttributeTextColor，定制文字颜色。

UITextAttributeTextShadowColor，定制文字的阴影色。

UITextAttributeTextShadowOffset，定制阴影的偏移位置。

UITextAttributeFont，定制文本字体。

 

// Settitletext attributes    

NSMutableDictionary *attributes= [[NSMutableDictionary alloc] init];

    

[attributessetValue:[UIColor blackColor] forKey:UITextAttributeTextColor];    

[attributessetValue:[UIColor whiteColor] forKey:UITextAttributeTextShadowColor];    

[attributessetValue:[NSValue valueWithUIOffset:UIOffsetMake(0, 1)]forKey:UITextAttributeTextShadowOffset];    

[attributessetValue:[UIFont fontWithName:@"Verdana"size:0.0] forKey:UITextAttributeFont];      

[[UIBarButtonItemappearance] setTitleTextAttributes:attributes forState:UIControlStateNormal];    

[attributesrelease];