XCODE 6.1 创建新白空应用

1.新建一个single view application
2.打开 Info.plist，删除里面的  Launch screen interface file....以及 Main storyboard file base name...
3.删除Main.storyboard以及LaunchScreen.xib
4.在AppDelegate.m修改如下（其中MainViewController是自己新建的 viewController）

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds] ];
self.window.rootViewController = [[MainViewController alloc]init];
[self.window makeKeyAndVisible];
return YES;
}