iOS程序初始化

1. 先初始化self.window

2. self.viewController

3. self.window.rootViewController

4. 显示, [self.window makeKeyAndVisible]

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

{

    self.window = [[UIWindowalloc] initWithFrame:[[UIScreenmainScreen] bounds]];

    // Override point for customization after application launch.

if ([[UIDevicecurrentDevice] userInterfaceIdiom] ==UIUserInterfaceIdiomPhone) {

    self.viewController = [[OTViewControlleralloc] initWithNibName:@"OTViewController_iPhone"bundle:nil];

} else {

    self.viewController = [[OTViewControlleralloc] initWithNibName:@"OTViewController_iPad"bundle:nil];

}

self.window.rootViewController =self.viewController;

    [self.windowmakeKeyAndVisible];

    return YES;

}