11.09创建控制器和创建视图的多种方式

（1）sb   // 传niu就相当于[NSBundle mainbundle]；
  UIStoryboard *sb = [UIStoryboard storyboardWithName:@"MYStoryBoard" bundle:nil];
 
    self.window.rootViewController =  [sb instantiateInitialViewController];
 
（2）sb+可重用标示
　　UIStoryboard *sb = [UIStoryboard storyboardWithName:@"MYStoryBoard" bundle:nil];
   
    UIViewController *control =  [sb instantiateViewControllerWithIdentifier:@"MYSB"];
（3）xib ： xib需要一个输出口
    MYViewController *con = [[MYViewController alloc] initWithNibName:@"MYViewController" bundle:nil];
   
    self.window.rootViewController = con;
（4）纯代码
 

// 1.纯代码
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
   
    self.window.backgroundColor = [UIColor clearColor];
   
    self.window.rootViewController = [[ViewController alloc] init];
   
    [self.window makeKeyAndVisible];