UIAppearance

iOS5提供了一个比较强大的工具UIAppearance，可以轻松的统一你的界面，它提供如下两个方法：

+ (id)appearance

+ (id)appearanceWhenContainedIn:(Class <>)ContainerClass,...

第一个方法是统一全部改，比如你设置UINavBar的tintColor，你可以这样写：[[UINavigationBar appearance] setTintColor:myColor];
第二个方法是当出现在某个类的出现时候才会改变：例如：

[[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], [UIPopoverController class], nil] setTintColor:myPopoverNavBarColor];

       另外其它的UI外观修改如下：

       首先定义两个值：

 //这样方便下面多个UI界面设置，textAttributes:字体
 id appearance;
 NSDictionary *textAttributes = nil;

1.导航条

代码如下：

 //导航条
 {
     appearance = [UINavigationBar appearance];
     UIImage *navBackgroundImg =[UIImage imageNamed:@"background_nav"];

     [appearance setBackgroundImage:navBackgroundImg forBarMetrics:UIBarMetricsDefault];
 }

2.标签栏（UITabbar）

代码如下：

 //标签栏
 {
     appearance = [UITabBar appearance];
     UIImage *tabBarBackGroungImg =[UIImage imageNamed:@"tabbar_background"];
     [appearance setBackgroundImage:tabBarBackGroungImg];

     UIImage * selectionIndicatorImage =[[UIImage imageNamed:@"tabbar_slider"]resizableImageWithCapInsets:UIEdgeInsetsMake(4, 0, 0, 0)] ;
     [appearance setSelectionIndicatorImage:selectionIndicatorImage];
 }

3.分段控件（UISegmentControl）

代码如下：

 //Segmente未选中背景
 {
     //cap insets用来指定哪些区域是固定不变的，未制定的区域则会repeat
     UIImage *segmentSelected = [[UIImage imageNamed:@"bg_o.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(5, 5, 5, 5)];

     UIImage *segmentUnselected = [[UIImage imageNamed:@"bg.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(5, 5, 5, 5)];

     UIImage *segmentSelectedUnselected = [UIImage imageNamed:@"line.png"] ;

     UIImage *segUnselectedSelected = [UIImage imageNamed:@"line.png"] ;

     UIImage *segmentUnselectedUnselected = [UIImage imageNamed:@"line.png"];


     appearance = [UISegmentedControl appearance];

     [appearance setBackgroundImage:segmentUnselected
                           forState:stateNormal
                         barMetrics:UIBarMetricsDefault];

     //Segmente选中背景
     [appearance setBackgroundImage:segmentSelected
                           forState:stateSelected
                         barMetrics:UIBarMetricsDefault];

     //Segmente左右都未选中时的分割线
     //BarMetrics表示navigation bar的状态，UIBarMetricsDefault 表示portrait状态（44pixel height），UIBarMetricsLandscapePhone 表示landscape状态（32pixel height）

     [appearance setDividerImage:segmentUnselectedUnselected
             forLeftSegmentState:stateNormal
               rightSegmentState:stateNormal
                      barMetrics:UIBarMetricsDefault];

     [appearance setDividerImage:segmentSelectedUnselected
             forLeftSegmentState:stateSelected
               rightSegmentState:stateNormal
                      barMetrics:UIBarMetricsDefault];

     [appearance setDividerImage:segUnselectedSelected
             forLeftSegmentState:stateNormal
               rightSegmentState:stateSelected
                      barMetrics:UIBarMetricsDefault];

     //字体
     textAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                       BAR_BUTTON_TITLE_SHADOW_COLOR,UITextAttributeTextColor,
                       BAR_BUTTON_TITLE_FONT,UITextAttributeFont,
                       BAR_BUTTON_TITLE_TEXT_COLOR,UITextAttributeTextShadowColor,
                       [NSValue valueWithCGSize:CGSizeMake(1, 1)],UITextAttributeTextShadowOffset,
                       nil];

     [appearance setTitleTextAttributes:textAttributes forState:1];

     textAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                       BAR_BUTTON_TITLE_TEXT_COLOR,UITextAttributeTextColor,
                       BAR_BUTTON_TITLE_FONT,UITextAttributeFont,
                       BAR_BUTTON_TITLE_SHADOW_COLOR,UITextAttributeTextShadowColor,
                       [NSValue valueWithCGSize:CGSizeMake(1, 1)],UITextAttributeTextShadowOffset,
                       nil];

     [appearance setTitleTextAttributes:textAttributes forState:0];
 }

4.UIBarbutton

注意：UIBarbutton有leftBarButton，rightBarButton和backBarButton，其中backBarButton由于带有箭头，需要单独设置。

barButton背景设置是ios6.0及以后的，而backbutton是ios5.0及以后的，这里要注意！

代码如下：

 //UIBarButtonItem
 {
     //只是修改导航条上的UIBarButtonItem
     appearance = [UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil];
     //backBarButton和leftBarButton，rightBarButton的字体同时设置
     textAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                       BAR_BUTTON_TITLE_TEXT_COLOR,UITextAttributeTextColor,
                       BAR_BUTTON_TITLE_FONT,UITextAttributeFont,
                       BAR_BUTTON_TITLE_SHADOW_COLOR,UITextAttributeTextShadowColor,
                       [NSValue valueWithCGSize:CGSizeMake(1, 1)],UITextAttributeTextShadowOffset,
                       nil];

     [appearance setTitleTextAttributes:textAttributes forState:0];

     textAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                       BAR_BUTTON_TITLE_SHADOW_COLOR,UITextAttributeTextColor,
                       BAR_BUTTON_TITLE_FONT,UITextAttributeFont,
                       BAR_BUTTON_TITLE_TEXT_COLOR,UITextAttributeTextShadowColor,
                       [NSValue valueWithCGSize:CGSizeMake(1, 1)],UITextAttributeTextShadowOffset,
                       nil];

     [appearance setTitleTextAttributes:textAttributes forState:1];

     UIImage *leftButton = [[UIImage imageNamed:@"bgLeftButton.png"] stretchableImageWithLeftCapWidth:14 topCapHeight:0];

     UIImage *normalButton = [[UIImage imageNamed:@"bgNormalButton.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];

     //leftBarButton，rightBarButton背景
     [appearance setBackgroundImage:normalButton
                           forState:UIControlStateNormal
                              style:UIBarButtonItemStyleBordered
                         barMetrics:UIBarMetricsDefault];

     [appearance setBackgroundImage:normalButton
                           forState:UIControlStateHighlighted
                              style:UIBarButtonItemStyleBordered
                         barMetrics:UIBarMetricsDefault];

     //单独设置backBarButton背景
     [appearance setBackButtonBackgroundImage:leftButton
                                     forState:0
                                   barMetrics:UIBarMetricsDefault];

     [appearance setBackButtonBackgroundImage:leftButton
                                     forState:1
                                   barMetrics:UIBarMetricsDefault];

     [appearance setBackButtonTitlePositionAdjustment:UIOffsetMake(2, -1)
                                        forBarMetrics:UIBarMetricsDefault];

 }

5.工具栏（UIToolbar）

代码如下：

 //toolBar
 {
     appearance = [UIToolbar appearance];
     //样式和背景二选一即可，看需求了
     //样式（黑色半透明，不透明等）设置
     [appearance setBarStyle:UIBarStyleBlackTranslucent];
     //背景设置
     [appearance setBackgroundImage:[UIImage imageNamed:@"background_nav.png"]
                 forToolbarPosition:UIToolbarPositionAny barMetrics:UIBarMetricsDefault];
 }

补充一个需要注意的地方：全局的设置最好在所有界面初始化前开始设置，否则可能失效。

一般写在appDelegate.m文件中。

原文连接：http://blog.csdn.net/shenjx1225/article/details/8552449