如何快速嵌入带有拆分视图控制器的标签栏控制器？

1）通过xcode创建示例主/明细

2）TabBarController在情节提要上拖动

3）将更TabBarController改为初始视图控制器。

4）控制从拖动TabBarController到SplitViewController

5）SplitViewController在故事板上指定标题

6）在应用程序委托中，替换对的引用，SplitViewController如下所示。

let tabBarViewController = self.window!.rootViewController as! UITabBarController
print(tabBarViewController.viewControllers?.count)
var splitViewController:UISplitViewController? = nil
for viewController in tabBarViewController.viewControllers! {
if viewController.title == "Master" {
    splitViewController = viewController as? UISplitViewController
}
}

let navigationController = splitViewController!.viewControllers[splitViewController!.viewControllers.count-1] as! UINavigationController
navigationController.topViewController!.navigationItem.leftBarButtonItem = splitViewController!.displayModeButtonItem()
splitViewController!.delegate = self