1>創建程序載入界面

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    //1>創建窗口

    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];

    //2>設置窗口的根控制器

    UITabBarController *tabBarController = [[UITabBarController alloc] init];

    self.window.rootViewController = tabBarController;

    //3>顯示窗口

    [self.window makeKeyAndVisible];

    return YES;

}

2>LaunchImage配置

  LaunchImage.launchimage文件下的Contents.json文件中記錄了LaunchImage的詳細配置:

3>取消APP圖標渲染

4>程序加載時隱藏狀態欄

  在程序加載完成后如需恢復狀態欄顯示,可以在didFinishLaunchingWithOptions方法中調用[application setStatusBarHidden:NO]方法;

5>添加TabBar控制器及其子控制器

  自定義一個TabBarViewController類繼承UITabBarController類用來創建自定義的TabBarView,并在該類中的viewDidLoad方法中創建子控制器

- (void)viewDidLoad

{

    [super viewDidLoad];

    //添加子控制器

    UIViewController *home = [[UIViewController alloc] init];

    home.view.backgroundColor = [UIColor redColor];

    home.tabBarItem.title = @"首頁";

    home.tabBarItem.image = [UIImage imageNamed:@"tabbar_home"];

    [home.tabBarItemsetSelectedImage:[UIImage imageNamed:@"tabbar_home_selected"]];

    [self addChildViewController:home];

    UIViewController *message = [[UIViewControlleralloc] init];

    message.view.backgroundColor = [UIColor orangeColor];

    message.tabBarItem.title = @"消息";

    message.tabBarItem.image = [UIImage imageNamed:@"tabbar_message_center"];

    [message.tabBarItem setSelectedImage:[UIImage imageNamed:@"tabbar_message_center_selected"]];

    [self addChildViewController:message];

    UIViewController *discover = [[UIViewControlleralloc] init];

    discover.view.backgroundColor = [UIColor greenColor];

    discover.tabBarItem.title = @"發現";

    discover.tabBarItem.image = [UIImage imageNamed:@"tabbar_discover"];

    [discover.tabBarItem setSelectedImage:[UIImage imageNamed:@"tabbar_discover_selected"]];

    [self addChildViewController:discover];

    UIViewController *PRofile = [[UIViewController alloc] init];

    profile.view.backgroundColor = [UIColor blueColor];

    profile.tabBarItem.title = @"我";

    profile.tabBarItem.image = [UIImage imageNamed:@"tabbar_profile"];

    [profile.tabBarItem setSelectedImage:[UIImage imageNamed:@"tabbar_profile_selected"]];

    [self addChildViewController:profile];

}

6>渲染圖片

    在iOS7中，會對selectedImage的圖片再次渲染為藍色，要想顯示原圖，就必須要取消渲染；

    取消渲染調用的方法：

    selectedImage = [selectedImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

7>優化添加子控制器代碼

    將添加子控制器到TabBarViewController的代碼進行優化，建立如下方法：

- (void)addOneChildViewController:(UIViewController *)viewController withTitle:(NSString *)title imageName:(NSString *)imageName selectedImageName:(NSString *)selectedImageName

{

    viewController.view.backgroundColor = ZFRandomColor;

    viewController.tabBarItem.title = title;

    viewController.tabBarItem.image = [UIImage imageNamed:imageName];

    UIImage *image = [UIImage imageNamed:selectedImageName];

if (iOS7) {

        image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

    }

    [viewController.tabBarItem setSelectedImage:image];

    [self addChildViewController:viewController];

}

    其中ZFRandomColor和iOS7為自定義宏,其宏定義在Prefix.pch文件下:

#ifdef __OBJC__

    #import <UIKit/UIKit.h>

    #import <Foundation/Foundation.h>

    #import <CoreData/CoreData.h>

    #define ZFRandomColor [UIColor colorWithRed:arc4random_uniform(256)/255.0 green:arc4random_uniform(256)/255.0 blue:arc4random_uniform(256)/255.0 alpha:1.0]

    #define iOS7 [[UIDevice currentDevice].systemVersion doubleValue] >= 7.0

#endif

    由于imageWithRenderingMode方法只在iOS7環境下有效,因此此處代碼需要添加條件判斷語句進行系統適配,通過獲取當前運行環境的系統版本來判斷是否編譯此方法;

8>圖片適配

    為UIImage添加一個分類,用于image的系統適配:

@implementation UIImage (Extension)

+ (UIImage *)imageWithName:(NSString *)imageName

{

　　UIImage *image = nil;

　　if (iOS7) {

　　NSString *name = [imageName stringByAppendingString:@"_os7"];

      image = [UIImage imageNamed:name];

    }

if (!image) {

        image = [UIImage imageNamed:imageName];

    }

return image;

}

@end