OS5開始你就可以改變導航欄的背景圖片 導航欄的背景圖片必須是下列高度：44 BarButton 30

想定製導航欄嗎？從iOS5開始你就可以改變導航欄的背景圖片、tintcolor或者標題文本。

這裏我們將介紹如何在Xcode中定製導航欄。

 

從這裏你可以下載到本文用到的按鈕： Buttons.zip

首先需要獲取UINavigationController引用。你可以在創建UINavigationController時定製導航欄，也可以在ViewController加載到UINavigationController時定製導航欄。

打開要引用UINavigationController的類，在viewDidLoad方法中定製導航欄的背景圖片，如下列代碼所示：

 

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];

 

 

導航欄的背景圖片必須是下列高度：

豎屏：44px(retina 屏則爲 88px)
橫屏：32px (retina 屏則爲 64px)

 

BarButton（包括backButton）的背景圖片用backgroundimage屬性設置。BarButton的背景圖片必須是下列高度：

豎屏：30px(retina 屏則爲 60px)
橫屏：24px(retina 屏則爲 48px)

 

如果標題文本過長（超過按鈕圖片的寬度）圖片將被縮放。

   

// 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];

 

還可以通過titleTextAttriutes屬性定製UIBarButton。setTitleTextAttributes:方法用一個NSDictionary參數指定所需選項：

UITextAttributeTextColor，定製文字顏色。

UITextAttributeTextShadowColor，定製文字的陰影色。

UITextAttributeTextShadowOffset，定製陰影的偏移位置。

UITextAttributeFont，定製文本字體。

 

// 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];