UISplitViewController是iPad特有的系统方法，主要效果就是呈现iPad的经典切割界面

代码创建实例：

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

{

    MyFirstViewController* firstVC = [[MyFirstViewController alloc] initWithNibName:@"FirstNib" bundle:nil];

    MySecondViewController* secondVC = [[MySecondViewController alloc] initWithNibName:@"SecondNib" bundle:nil];

    UISplitViewController* splitVC = [[UISplitViewController alloc] init];

    splitVC.viewControllers = [NSArray arrayWithObjects:firstVC, secondVC, nil];

    [window addSubview:splitVC.view];

    [window makeKeyAndVisible];

    return YES;

}