旋转的风扇（RoundDisk)

#import "AppDelegate.h"
//加入头文件
#import "RoundDiskViewController.h"

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    
    RoundDiskViewController *roundViewController = [[RoundDiskViewController alloc] init];
    [self.window addSubview:roundViewController.view];

    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}