iOS UIAppearance使用详解

转载自：iOS UIAppearance使用详解

iOS5及其以后提供了一个比较强大的工具UIAppearance，我们通过UIAppearance设置一些UI的全局效果，这样就可以很方便的实现UI的自定义效果又能最简单的实现统一界面风格，它提供如下两个方法。

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

这个方法可设置某个类的改变：例如：设置UIBarButtonItem 在UINavigationBar、UIPopoverController、UITabbar中的效果。就可以这样写

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

• • (id)appearance

这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];

请注意：

使用appearance设置UI效果最好采用全局的设置，在所有界面初始化前开始设置，否则可能失效。

具体UI外观修改如下：

1.修改导航栏背景

UINavigationBar * appearance = [UINavigationBar appearance];

UIImage *navBackgroundImg =[UIImage imageNamed:@"navBg.png”];

[appearance setBackgroundImage:navBackgroundImg forBarMetrics:UIBarMetricsDefault];

2.标签栏（UITabbar）

UITabBar *appearance = [UITabBar appearance];
    //设置背景图片
    [appearance setBackgroundImage:[UIImage imageNamed:@"tabbar_bg.png"]];
    //门置选择item的背景图片
    UIImage * selectionIndicatorImage =[[UIImage imageNamed:@"tabbar_slider"]resizableImageWithCapInsets:UIEdgeInsetsMake(4, 0, 0, 0)] ;
    [appearance setSelectionIndicatorImage:selectionIndicatorImage];

3.分段控件（UISegmentControl）

 UISegmentedControl *appearance = [UISegmentedControl appearance];

    //Segmenteg正常背景
    [appearance setBackgroundImage:[UIImage imageNamed:@"Segmente.png"]
                          forState:UIControlStateNormal
                        barMetrics:UIBarMetricsDefault];

    //Segmente选中背景
    [appearance setBackgroundImage:[UIImage imageNamed:@"Segmente_a.png"]
                          forState:UIControlStateSelected
                        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:[UIImage imageNamed:@"Segmente_line.png"]
            forLeftSegmentState:UIControlStateNormal
              rightSegmentState:UIControlStateNormal
                     barMetrics:UIBarMetricsDefault];

    [appearance setDividerImage:[UIImage imageNamed:@"Segmente_line.png"]
            forLeftSegmentState:UIControlStateSelected
              rightSegmentState:UIControlStateNormal
                     barMetrics:UIBarMetricsDefault];

    [appearance setDividerImage:[UIImage imageNamed:@"Segmente_line.png"]
            forLeftSegmentState:UIControlStateNormal
              rightSegmentState:UIControlStateSelected
                     barMetrics:UIBarMetricsDefault];

    //字体
    NSDictionary *textAttributes1 = @{UITextAttributeFont: [UIFont systemFontOfSize:18],
                                     UITextAttributeTextColor: [UIColor blueColor],
                                     UITextAttributeTextShadowColor: [UIColor whiteColor],
                                     UITextAttributeTextShadowOffset: [NSValue valueWithCGSize:CGSizeMake(1, 1)]};

    [appearance setTitleTextAttributes:textAttributes1 forState:1];

    NSDictionary *textAttributes2 = @{UITextAttributeFont: [UIFont systemFontOfSize:18],
                                     UITextAttributeTextColor: [UIColor whiteColor],
                                     UITextAttributeTextShadowColor: [UIColor blackColor],
                                     UITextAttributeTextShadowOffset: [NSValue valueWithCGSize:CGSizeMake(1, 1)]};

    [appearance setTitleTextAttributes:textAttributes2 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！

//修改导航条上的UIBarButtonItem
    UIBarButtonItem *appearance = [UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil];

    //设置导航栏的字体包括backBarButton和leftBarButton，rightBarButton的字体
    NSDictionary *textAttributes = @{UITextAttributeFont: [UIFont systemFontOfSize:18],
                                     UITextAttributeTextColor: [UIColor blueColor],
                                     UITextAttributeTextShadowColor: [UIColor whiteColor],
                                     UITextAttributeTextShadowOffset: [NSValue valueWithCGSize:CGSizeMake(1, 1)]};

    [appearance setTitleTextAttributes:textAttributes forState:1];//forState为0时为下正常状态，为1时为点击状态。


    //修改leftBarButton，rightBarButton背景效果
    [appearance setBackgroundImage:[UIImage imageNamed:@"navBarButton.png"]
                          forState:UIControlStateNormal
                             style:UIBarButtonItemStyleBordered
                        barMetrics:UIBarMetricsDefault];

    [appearance setBackgroundImage:[UIImage imageNamed:@"navBarButton_a.png"]
                          forState:UIControlStateHighlighted
                             style:UIBarButtonItemStyleBordered
                        barMetrics:UIBarMetricsDefault];


    //backBarButton需要单独设置背景效果。只能在ios6.0以后才能用
    [appearance setBackButtonBackgroundImage:[UIImage imageNamed:@"nav_bg.png"]
                                    forState:0
                                  barMetrics:UIBarMetricsDefault];

    [appearance setBackButtonBackgroundImage:[UIImage imageNamed:@"work.png"]
                                    forState:1
                                  barMetrics:UIBarMetricsDefault];

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

6.工具栏（UIToolbar）

UIToolbar *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:@"toolbarBg.png"]
                forToolbarPosition:UIToolbarPositionAny
                        barMetrics:UIBarMetricsDefault];