复用

1.

Xcode6.0.1貌似创建的项目只能带有MainStoryboard，要么就是完全empty的，didFinishLaunchingWithOptions方法自然也就是空的，或许此代码日后经常需要用到。

<pre name="code" class="objc">- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];        self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    return YES;}