Sorry for the long and possibly confusing question. In this I have 2 main problems with my code, those being: 1- When I embed my viewControllers in a UINavigationController and add a bar button item, nothing appears, yet it appears when I add it to the pageViewController. Secondly, I am wondering if there is a way to do this differently and use one button on the pageView (which appears on all viewcontrollers in it) and just determine what the user was looking at when they pressed the button and are taken to another viewcontroller.
I am trying to build a page-based application, and I have set up the application with 7 view controllers (One for each day of the week). I then have an AddViewController, where users can add data to a certain day. I was wondering if there is a way to only use 1 addView linked to the NavBar on the PageViewController, as when I embed all other viewControllers and add a bar button, it does not show up.
With the pageViewController being embedded, this is what it looks like with a bar button on it.
This then leads to:
Which works well, however I am wanting to pass data to various arrays (one for each viewController), and I want to know which ViewController the user wishes to add to (based off what day they were on). Is there a way to determine this and then unwind to the viewController and append the right data to the right array or should I have one addView per dayViewController? If that is the case, I am coming across the issue whereby the bar button items do not appear on the viewControllers when they are embedded in a navigationController. It looks like this:
StoryBoard: (Example: MondayViewController)
The outcome is a missing barButton: (Keep in mind I changed the tint Colour to white so it would be visible)
I was wondering if anyone has the answer to either of my problems, and once again, thanks for taking the time to look at this array of questions in one problem.
Any suggestions are welcome !
Rowan,
You can do this:
Create an UINavigationViewController and then embed an UIPageViewController in it.
In the data source for the UIPageViewController implement these two methods:
- pageViewController:viewControllerBeforeViewController:
- pageViewController:viewControllerAfterViewController:
Here you will return the correct instance of your DayViewController for each position (or nil if you are on the first/last page). Your data model would also be set here.
Add your "Add" bar button to the navigation bar of the UIPageViewController and let it push your AddViewController. When pushing the AddViewController provide to it the info on which day is currently visible. You will probably need to keep track of this your self. Use the - pageViewController:didFinishAnimating:previousViewControllers:transitionCompleted: method of the UIPageViewController delegate.
Related
More viewcontroller images are showing up in default blue background instead on original images. I want to change them to original images and also want to increase UITableViewCell's height.
I have tried implementing tableview delegate methods on UITabbarController, but nothing working out.
Even moreNavigationController is also not changing.
1) Where do i have to write these custom methods viewDidLoad or viewWillAppear. Also shouldSelectViewController is not getting called. First time when i select a tabbar item it is being called and when i select the more item it is not getting called.
2) Where should i implement UITableView delegate methods.
My screen -
required screen -
A solution using swift is helpful. Thanks in advance.
I got the requirement working. The step wise procedure I followed is
Take a ViewController which extends UITabbarController.
Take an array with five elements exactly.(If more than five then default More functionality gets enabled).
First four tabs as required and fifth should be 'More' tab. With required tab images.
For 'More' tab create a View Controller which extends UITableView delegates and datasources. And implement respective methods of delegate and datasources.
Take an array of the Cells you want to display and display them.
Link this 'More' View Controller to the 'More' tab.
Change the images in tableview in cellForRowAtIndexPath method.
Run the application and check by selecting 'More' tab. This time it should show the changed UI.
When each cell should show different View Controllers on selecting the cells, then segue to different view controllers using the segues from ViewController (Not segue from the tablecell). Define a unique segue id for each segue and show the viewcontrollers based on switch or ifelse conditions in shouldSelectViewController using performSegueWithIdentifier.
Thanks #KKRocks for the valuable links.
There's some content to be unpacked here. I am not entirely certain I fully understand the question but I'll go ahead and reply partially as best I can.
ViewDidLoad and ViewWillAppear
You add code in viewDidLoad for initialization. This method will run when your view is originally loaded and unless you're instantiating the controller every time it will only run once ( in this case you dont because you're using the prebuilt tabbar system which takes care of that for you)
So I would add the styling code in viewDidLoad()
When a viewController is to be displayed, viewWillAppear() will be called. This will happen every time so if you need to perform repetitive tasks like network calls, restyling based on some other data, refreshing your tables, you should do it here.
Table methods
For doing whatever you need to do with a table you will most likely need both UITableViewDelegate and UITableViewDataSource to your view controller. Look up any UITableView tutorial online they're many very comprehensive and will explain how to add all the table methods you need in your viewController.
I'm new to ios. I'm uising uitabbar. I want to store in ram only currently selected viewcontroller of the secific UItabbarControllerItem is there a way to implement it?
UITabbar is loading all viewcontrollers in ram. I don't like it. I want to make it work following way: store in memory only 1 selected viewcontroller,
when user selects othe uitabbar item it loads again new viewcontroller
Are you sure you wanna do this? IOS is responsible for managing memory, but try this.
When you load a controller you can make a loop over "controllers" property of the tabbar and put a nil value to each. Be careful, don't put your current controller = nil.
tabbar.controllers is an array with the all the controllers of the tabbar. If you are in the second one, is the tabbar.controllers[1], don't put this one to nil.
If you want to go to other controller, you have to create it an assign to the tabbar.controllers. But, which position? the array only have one position, the current controller, and almost certainly will not work tabbar buttons. It will generate an exception and your app fall.
I do not recommend you do this, but yourself
i have one question about using multiple segues to one ViewController. Ill try to create an article management, so you can add/edit/delete articles.
When you add a new article you can choose between a maincategory and a subcategory, choose the article and then edit some inital values.
but if ill try to edit one of my selected articles, i would like to jump to the "latest" ViewController in navigation stack.
I thought i could easily create another segue to my last viewController, but ill always get an error when i try to load this segue (i guess this could be a problem with the existing NavigationController).
I could provide some code, but i dont know if this is a possible solution to solve such things - or is there a better way?
Thanks in advance.
You can, but the new segue should take you to a navigation controller that just contains the last view controller (as the root). In this way you are duplicating the normal situation but with only 1 view controller.
If you wanted to allow the last view controller to have a 'back' button which took you to some 'earlier' screens (if that makes any kind of sense in your app) then you would need to write some code. It's more likely that other screens should be accessed via bar button items or similar (which would also likely be done in code).
I have the following setup in my app:
My initial view controller is a UITabBarController.
the tabs:
1)UINavigationController->PostListVC
2)UINavigationController->CategoriesListVC
3)UINavigationController->PostListVC
4)UINavigationController->PostListVC
5)UINavigationController->MoreViewController
As you can see, 3 tabs contain the same viewController class, but should not contain the same view controller object - the view will display different information based on information he gets form the AppDelegate.
What I did is I created 5 UINavigationControllers, connected them to the uitabbarcontroller, then created a rootViewController segue for 3 of them to the same PostListVC View - that way I don't need to maintain 3 designs of the same view.
The problem that I get is that only the first PostListVC gets created properly ( the leftmost in the tab bar ) - the other tabs that point to a PostListVC just show a black screen.
I've tried to illustrate the way I wire-up the storyboard using a 3-tab example:
As you can see, both the upper-most and lower-most views are connected to PostListVC.
I do not know what the issue is. I assume I'm using storyboards somewhat wrongly.
Does anybody know how I can fix this?
Thanks!
EDIT:
I have created a simple, example project (Xcode 5) that illustartes this issue:
http://www.speedyshare.com/Srwfg/TabBarProblem.zip
EDIT 2:
A modified version of the example, showing the problem with the offered solution:
http://speedy.sh/JkdGC/TabBarProblem-2.zip
There is no way to create different tabBarItems with this method, and there's no way to place the barItems so that they're not in a row - even if you try to chagne the order of segues.
As you said you need three different instances of PostListVC then you should create three different viewcontrollers of type PostListVC and connect each tab to its own. The class is the same but each tab gets its own instance.
I have got your example program to work BUT I don't know if the solution will work for your full project. Hopefully, it will put you on the correct track.
The solution is to have ONE (1) Navigation Controller / embedded root view but TWO (2) segues from the Tab Bar Controller. Here's the picture:
It looks like there's a problem with multiple UINavigationControllers linking to the same UIViewController. But no problem with the same UINavigationController linking to the same UIViewController provided they are instantiated separately through the UITabBarController.
Situation: two UITabBarController's, each with their own tabs, but last tab in both is identical so want one UIViewController to show content.
Issue at runtime: Shared item only appears in one of the tab sets when shown.
Question: anyone know a way to make this work?
Link to external graphic of storyboard setup: (sorry, don't have enough reputation to post images here!)
Storyboard graphic
An Xcode project with that storyboard:
XCode Project
Each tab content item has it's own UIViewController class. They contain no code except the line to make the back buttons work.
(Yes, I know this is odd. Real situation is an iPad app where tab controllers are shown in popovers; popovers are "property editors" where different objects have different properties, but all share a common set of properties... thus one tab for "unique" props, one shared tab content for the "common" props all objects have.)
I've found a couple ways around this to get the effect I want, but if this storyboard worked it would be a much easier solution.
-- Other info, somewhat unrelated to question --
Alternate solution I'm using: TabBarControllers only link to one VC as tab content. When that tab VC loads, I use code to (a) instantiate shared VC from storyboard by identifier, (b) add that new VC object to the TabBarController via [tabController setViewControllers:list animated:NO].
(Another possible solution I like even less: not using a TabBarController, and presenting content VC's with my own "tab" graphic drawn into them, each showing "myself" as selected. Yuk.)
So I have a working solution, I'm just curious as to why this doesn't work (just a known thing in iOS API, or some magical property setting that might render it functional?)
You can't put the same view controller instance into two tab controllers. The problem is that a view (UIView) instance can only have one parent view (superview). When you try to add the view controller to the 2nd tab, the view controller's view gets removed from its first parent (the first tab) and then added to the 2nd tab.
I stumbled upon your thread while running into the same issue today...
The solution is to just make a duplicate of the view controller in story board and attach the duplicate to the other tab bar controller.
I just did it and it works...
I think the 'rdelmar' is right about this... copy it and set it ..!!
I ran across this same issue today. I managed to come up with a workaround that seems to do the trick. The key is to add a layer of separation between the tabbar and the controller you want to reuse. From each tabbar, I created a relationship to a distinct UIViewController with a container view. Then you can do an 'embed' segue from the container to the controller you actually want to reuse as the tab view. It is not quite as clean as a direct connection (not sure why that is not supported) since you do have to create a controller class for each reuse case. It is still a better solution than the nightmare of having to duplicate the actual tab view ( as well as any additional views that connect to it) for every use.
Hope this helps. Let me know if anyone needs more details.