I'm using storyboards and I want two UIViewControllers to share the same controller class. I've done this and I've hooked up my UIImageViews to their IBOutlets.
When I call [day3 setImage:[UIImage imageNamed: #"1.png"]];
it doesn't change the image. Has this got anything to do with it sharing the same controller class as another view?
This view with the UIImageViews on is opened via push segue from the other view controlled by the same controller class.
Your problem is that although both views are using the same UIViewController, they are connected to different instances of them. Let's call our ViewController myViewController. When the new view is pushed it actually creates a whole new myViewController. So you now have two active in your app. One instance of myViewController for the first view and another for the second view. You can therefore not directly manipulate the views from the other view's instance of that controller.
In order to set properties you will need to communicate between the two instances of myViewController the same way you would as if they were entirely different ViewControllers. If you need further help or explanation let me know.
Related
I have an ios app written in swift and there I have a UIViewController with a container on half of the screen. This container has embedded UITableViewController and I want to display there some data that I'm fetching from my webservice. The problem is that to fetch the data from web service I need an unique id number that I store in the UIViewController. So how can I pass that data from one controller to another?
I have a project on github (written in Objective-C) that does exactly what you want. It has the horribly unoriginal name "test".
It has a master view controller with 2 child view controllers, each of which is a subclass of UITableViewController set up to manage static table views. (That detail doesn't really matter. It's the method of setting up connections between parent and child view controllers that addresses your question.)
The idea is that you set up your child view controller in a container view and link it in with an embed segue.
When you use an embed segue then prepareForSegue fires when the views are loaded. In your prepareForSegue you save a reference to your child view controller(s) if you need to call it/them, and make yourself each child's delegate if you need it to call you.
The code would be different in Swift but the concept is identical.
I have a ProductDescription ViewController that gets called from a ProductTable UITableView that I have placed in many ViewControllers.
It doesn't seem very efficient to ctrl+drag a segue for each tableView in the Storyboard, as I have approx 20 of them.
How does one do this programmatically?
You have several options within UIKit to programmatically show a view controller without using a segue:
Push a view controller onto the navigation stack:
pushViewController:animated:
showViewController:sender:
Present a view controller modally:
presentViewController:animated:completion:
The real answer here is to use storyboard references. You shouldn't have the same thing in twenty different spots all trying to link to the same view controller to the point of asking this question.
So, let's create Product.storyboard, a storyboard which simply has two view controllers:
ProductTableViewController
ProductDescriptionViewController
And the appropriate segue between the two controllers.
Now, everywhere else in any of your other storyboards that want to use these controllers with this relationship, simply add a storyboard reference, add a container view controller, and add an embed segue between the container view and the appropriate view controller in the product storyboard.
You can accomplish this same effect even without using storyboard references. Ultimately, the main point is to use container views and make embed segues from everywhere you need this relationship to the first of these two controllers, and then there's just a single relationship created between the two product view controllers.
I am trying to create a class that is similar in functionality to the UITabBarController, but with some fundamentally different functionality. It is called a dropdownViewController and has a primary content view with a UITabBar-like interface at the top of the screen that allows for other UIViewControllers to be modally presented and dismissed over this primary viewController.
I would like this class to be able to be set up using the storyboard to some extent, and I have created a custom Segue that connects my dropDownViewController class with each of its child viewControllers.
My current solution is to assign identifiers to each of the Segues that are then stored in array within the dropdownViewController. I can call the segues programmatically using the performSegueWithIdentifer: method, but this solution isn't as flexible or intuitive as I would like to to be.
Right now, all the custom Segues that I have setup are connected to the "manual" triggered segue in the storyboard connections panel for the dropdownViewController. (I would put screenshots but this is my first post)
However, I want to mimic the functionality of the UITabBarController class, which has an alternate triggered segue in the storyboard connections panel called viewControllers that each of its child views are assigned to. Unless there are some compile-time macros handling these story board interactions, I assume that the UITabBarController uses these connections to determine what it's view controllers are. However, I can't figure out how to setup this functionality with my own class
After searching around for a solution, it seems likely that this is functionality Apple kept for its own use and is limited to their own classes as a feature in Xcode, but if anyone has solutions or ideas it would be greatly appreciated.
I haven't tried this, but I think you should be able to do it with your own custom segues. In the perform method, you would just add the destination view controller to the source view controller's (DropDownViewController) array of view controllers. In the DropDownViewController's viewDidLoad method (or maybe in an initializer or awakeFromNib, not sure which is most appropriate), you would execute all these segues so that they run right after the controller is loaded like is done for a tab bar controller.
I have created and drawn out a custom UIViewController called AutocompleteVC in my Main storyboard. AutocompleteVC will be used in several different places/storyboards and with different dimensions.
For example, in my Transit storyboard, shown below,, there is a custom UIViewController called TransitVC, shown on the left. In TransitVC, I have a container view with an IBOutlet called autocompleteContainerView. autocompleteContainerView has a segue called autocompleteEmbedSegue to a generic UIViewController, shown on the right in red.
The goal is to have TransitVC hold AutocompleteVC inside autocompleteContainerView. But I'm having trouble getting this to work. The reason I want to do this inside a container view is so I can use autolayout to set constraints on it. Otherwise, I know how to do this purely in code.
I believe my approach might be flawed. What is the correct approach to do this if I want to maximize storyboard usage.
I'm not sure what you are asking. Setting up a parent/child relationship with a container view is very easy, exactly as you have outlined. Just create a container view inside the parent view controller, create the child view controller scene, and then control-drag from the container view to the child view controller to create the embed segue.
I have a storyboard with a navigation controller that leads to an UIVIewController that I want to reuse. That UIVIewController has a ParentUIViewController that has all the basic functionalities for all the UIVIewControllers that I am reusing.
Currently I am copying and pasting (meh) and then I change the class of the UIViewController to the ChildUIVIewController that I want to use (ChildUIViewController extends ParentUIViewController).
But this sounds like a bad solution. Everytime I want to change the ParentViewController visually I need to update, manually, all other ChildViewControllers.
I have tried to create a xib for the ParentViewController but the xib isn't loaded because I need a xib with the name of the ChildViewController. I have created it and then said the class is the ParentViewController but it crashes in the segue.
EDIT
I have created an example of the status of my problem
https://github.com/tiagoalmeida/storyboardexample
Note that the ParentViewController has a set of logic way more complicated that is not illustrated there. Also note that I am also using a TableView. I hope that this can illustrate the problem.
Keep the logic on the parentViewController and the UI Part on the child UIViewControllers. If you need to create a new UIViewController, you will create a child that will have a corresponding XIB (or get rid of XIBs and create the interface by hand).
Have you considered looping back into the same UIViewController via a "phantom button"?
Have a look at this: UIStoryboard Power Drill, Batteries included
Essentially you can drag a Bar Button Item into the little black bar under the View Controller in Storyboard (the 1 with View Controller, First Responder, and Exit icons; sorry, I don't recall what this is called exactly), then you can control+drag from that button back into the UIViewController for a Push segue. This should create a loop segue in your Storyboard. All you need to do next is give that segue an identifier, programmatically call it from your code using [self performSegueWithIdentifier:], then implement -(void)prepareForSegue: and use [segue destinationViewController] to conditionally set the title and perhaps some flags so you can identify when to use different kinds of fetches (or other code variations) in the same Class code.