Segue from one ViewController to another ViewContr

问题:

In the interface builder I have a UITabBarController and it is set as the initial view controller. From the tab bar controller, I have linked three independent ViewControllers; two UIViewController's and one UITableViewController. I have embedded all three of these views inside UINavigationController's as each of these views will eventually segue to a new view.

Interface Builder

Problem:

I now want to link one of the UIViewController's to the UITableViewController using a button to segue to the table view. This way I can pass information, i.e. func prepareForSegue(), to the table view. I want to maintain the tab bar controller at the bottom, however I do not want to have the ability to go back to the previous UIViewController from the current UITableViewController via a UIBarButtonItem at the the top of the view; That is what the tab bar at the bottom is for.

However every time I segue "Show" the table view (it is actually a segue to the table views navigation controller), the navigation bars at the top and the bottom of the table view disappear. Is there anyway to prevent this from happening?

I have also tried segue "Show" directly to the table view, in which case the tab bar is visible, but then it displays a "back" button at the top of the view to segue back to the sending UIViewController. I am hesitant about accepting a solution that would just hide the back button, because I feel I will run into problems down the road when I want to navigate to a detail view from the table view itself, since I would be bypassing the UITableViewController's UINavigationController.

Any solutions would be greatly appreciated. I have been trying to solve this problem for hours and I'm about to put my head through my computer screen. Also I thought about just using tabBarController?.selectedIndex on the button click to shift to the table view, and then passing the information using NSUserDefaults, but this is out of the question since I would be passing a custom object, and would have to encode and decode every custom field.

回答1:

I you use a segue to get to it, as you say, you will still be using the UIViewController's UINavigationController which seems a bit messy. So I actually think selectedIndex is probably the best way to go as once you change to the UITableViewController you'll be in the correct navigation stack.

Instead of using NSUserDefaults, why not just reference the UITableView itself from the UIViewController, set the values you want, and then swap to it using self.tabBarController.selectedIndex.

So for your scenario above it, assuming the UITableViewContollrer is the third view in the UITabBarController, you would do something like the following:

1. Pass whatever you want into the UITabBarController by setting some pre-defined var in it. For example, if there was a String called saveMe in the UITableViewController, then do the following in the UIViewController:

   let navController = self.tabBarController?.viewControllers![2] as! UINavigationController
   let tableViewController = navController.viewControllers.first as! JarListTableViewController
   tableViewController.saveMe = "Saved string here"
   

2. Swap to the UITableViewController using:

   self.tabBarController?.selectedIndex = 2
   

The only issue with this is using selectedIndex won't perform a transition animation but not sure if you need this. This link could help if you do.