Swift 3-在启动时加载多个ViewController [英] Swift 3 - loading multiple ViewControllers at launch

问题描述

我正在制作一个选项卡式应用程序.它具有一个TabBarController和四个附加的ViewController.

I am working on making a tabbed app. It has a TabBarController and 4 ViewControllers attached to it.

默认情况下，在启动时仅加载FirstViewController.我想在通过选项卡菜单切换到第二个视图之前先加载FirstViewController和SecondViewController.

By default, at launch only FirstViewController is loaded. I would like to load both FirstViewController and SecondViewController at start before switching to the second view via tab menu.

到目前为止，我尝试创建的是自定义MyTabBarController类并尝试使用

What i tried so far is that I created custom MyTabBarController class and tried to use

var sv = SecondViewController()
sv.loadView()

在ViewDidLoad()中，但是在加载过程中导致了致命错误，因为(我猜)故事板中的mapView元素未加载.

in ViewDidLoad(), but it caused a fatal error during loading, because (my guess) mapView element from storyboard was not loaded.

同时加载使用情节提要元素的两个viewController的正确方法是什么?到目前为止，我所有其他尝试都没有成功.

What is the correct way to simultaneously load the two viewControllers which use storyboard elements? All my other tries have not been successful so far.

推荐答案

在主视图控制器中添加

var secondViewController:UIViewController!

在您的viewDidLoad中:

And in your viewDidLoad:

secondViewController: UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "yourIdentifier") as! SecondViewController

就是这样.当您要显示它时，请使用:

That's it. When you want to present it, use:

self.present(secondViewController, animated: true, completion: nil)

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