iphone：UISplitView

UINavigationController *nc = [self.splitViewController.viewControllers lastObject];

self.detailViewController = (SplitViewDetailViewController *)[nc topViewController];

有一个splitViewController属性，其viewControllers为一个含两个ViewController的数组，0-left，1-right in landscape

看文档：https://developer.apple.com/library/ios/#documentation/UIKit/Reference/UISplitViewController_class/Reference/Reference.html#//apple_ref/doc/uid/TP40009277

The array in this property must contain exactly two view controllers. The view controllers are presented left-to-right in the split view interface when it is in a landscape orientation. Thus, the view controller at index 0 is displayed on the left side and the view controller at index 1 is displayed on the right side of the interface.

The first view controller in this array is typically hidden when the device is in a portrait orientation. Assign a delegate object to the receiver if you want to coordinate the display of this view controller using a popover.

创建过程：

在StoryBoard中让Master Detail都Embed in navi..

然后先在AppDelegate的

didFinishLaunchingWithOptions中添加代码，使得splitView的delegate为DetailViewController

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
    UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
    splitViewController.delegate = (id)navigationController.topViewController;
    return YES;
}

在MasterVC中取得DetailVC

@property (strong, nonatomic) DetailViewController *detailViewController;

viewDidLoad：

UINavigationController *nc = [self.splitViewController.viewControllers lastObject];

self.detailViewController = (DetailViewController *)[nc topViewController];

self.detailViewController.detailItem = xxxx；

在DetailVC中，当然要遵循<UISplitViewControllerDelegate>

@property (strong, nonatomic) id detailItem;//in .h

@property (strong, nonatomic) UIPopoverController *masterPopoverController;//in .m

- (void)setDetailItem:(id)newDetailItem {

// Update the view.

}

#pragma mark - Split view

- (void)splitViewController:(UISplitViewController *)splitController willHideViewController:(UIViewController *)viewController withBarButtonItem:(UIBarButtonItem *)barButtonItem forPopoverController:(UIPopoverController *)popoverController
{
    barButtonItem.title = @"列表";
    [self.navigationItem setLeftBarButtonItem:barButtonItem animated:YES];
    self.masterPopoverController = popoverController;
}


- (void)splitViewController:(UISplitViewController *)splitController willShowViewController:(UIViewController *)viewController invalidatingBarButtonItem:(UIBarButtonItem *)barButtonItem
{
    // Called when the view is shown again in the split view, invalidating the button and popover controller.
    [self.navigationItem setLeftBarButtonItem:nil animated:YES];
    self.masterPopoverController = nil;
}

若DetailVC不止是一个ViewController，我们可以使MasterVC遵循<UISplitViewControllerDelegate>,实现其委托方法；让DetailVC遵循自定义的协议，其功能是使在land和port时隐藏\显示调出popover的barItem

然后在tableView:didSelectRowAtIndexPath：中实例化相应的DetailVC，

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Storyboard" bundle:nil];

FirstDetailViewController *newDetailViewController = [storyboard instantiateViewControllerWithIdentifier:@"v1"];

detailViewController = newDetailViewController;

当然也可以通过StoryBoard中的Segue代替实现实例化功能