1>创建程序载入界面

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

{

    //1>创建窗口

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

    //2>设置窗口的根控制器

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

    self.window.rootViewController = tabBarController;

    //3>显示窗口

    [self.window makeKeyAndVisible];

    return YES;

}

2>LaunchImage配置

  LaunchImage.launchimage文件下的Contents.json文件中记录了LaunchImage的详细配置:

3>取消APP图标渲染

4>程序加载时隐藏状态栏

  在程序加载完成后如需恢复状态栏显示,可以在didFinishLaunchingWithOptions方法中调用[application setStatusBarHidden:NO]方法;

5>添加TabBar控制器及其子控制器

  自定义一个TabBarViewController类继承UITabBarController类用来创建自定义的TabBarView,并在该类中的viewDidLoad方法中创建子控制器

- (void)viewDidLoad

{

    [super viewDidLoad];

    //添加子控制器

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

    home.view.backgroundColor = [UIColor redColor];

    home.tabBarItem.title = @"首页";

    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 = @"发现";

    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>渲染图片

    在iOS7中，会对selectedImage的图片再次渲染为蓝色，要想显示原图，就必须要取消渲染；

    取消渲染调用的方法：

    selectedImage = [selectedImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

7>优化添加子控制器代码

    将添加子控制器到TabBarViewController的代码进行优化，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为自定义宏,其宏定义在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环境下有效,因此此处代码需要添加条件判断语句进行系统适配,通过获取当前运行环境的系统版本来判断是否编译此方法;

8>图片适配

    为UIImage添加一个分类,用于image的系统适配:

@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