I'm using a weird setup in my splitview Ipad app where i need some help with.
I have a TVC and a Normal View side by side in the split view. When i select something in my TVC both the screens segue to another TVC and Normal View. This part works fine. I'm using the push method with destination Master Split & Detail Split.
The problem is going back. I want to press 1 button and unwind both segues. I do this by this method: https://github.com/bradley/iOSUnwindSegueProgramatically[1]
This has 1 problem tho. The button being clicked to activate my segues is located in the detail view. So the detail view segues back no problem. The Master view however does not segue i'm stuck on how to get that working the same way.
The other option i figured i could do is do a normal segue and than use a custom transition animation but that seems like more of a "hack". So i was wondering if i could segue my TVC back through the detail view.
I hope i'm being clear on how i'm setup and where i need to go.
Cheers,
There is a note in Matt Neuburg's iOS7 book that in some situations you need to subclass UISplitViewController, and put the unwind method in the subclass. You might try that (but be sure to remove it from the detail controller, since only the first one in the chain is called.)
Related
I am running into a problem here. I am presenting views with performSegueWithIdentifier. Everything goes smoothly. The problem is that as a test, I only have 2 viewControllers with some data in them and I have two buttons that call a segue back to the other VC. If I keep performingSegues, you can clearly see that the memory usage goes up every two segues by around 0.4Mb. This tells me that the Views are not being deleted/removed from the view stack and are just using memory. I would like to know the correct way of getting rid of the view that presents the other view by using performSegueWithIdentifier (of course, after it finished presenting the view, else it will not work I guess).
Could you point me in the right direction? I found some objective-c code that tried to do this but it was very extensive and I don't know much about objective-C, so it was a little hard for me to understand.
Thank you in advance for your help!
Cheers!
Edit:
I am doing a "manual segue". By this I mean I have two view controllers standing on their own. They are not embedded in any navigationVCs or something like that. I am using an "Adaptive Segue" of type "Show".
If your goal is to always keep one VC, and since you already have a manual segue, what you can do is, after presenting the next VC you can pop the existing VC from the root and assign the destination VC as your root VC like so
class ManualSegue: UIStoryboardSegue {
override func perform() {
sourceViewController.presentViewController(destinationViewController, animated: true) {
self.sourceViewController.navigationController?.popToRootViewControllerAnimated(false)
UIApplication.sharedApplication().delegate?.window??.rootViewController = self.destinationViewController
}
}
}
When you do normal segues, you are piling up new view controllers on top of the existing ones without dismissing them. That's why your memory usage keeps going up.
You need to provide more information before we can give you specific guidance. Are you doing modal segues or pushing onto a navigation stack?
If you're pushing, you want to pop to the view controller you came from. Think in terms of a stack of plates. When you push, you add plates to the stack. When you pop, you take plates off and reveal the plates (view controllers) underneath. Do a search in the Xcode help system on "PopTo" to find the methods that let you either pop back to a specific view controller or back to the root view controller of your navigation controller.
Modal view controllers stack on top of each other in a similar fashion, but without the origination of a navigation controller. If you've pushed a series of one or more modals and you send the dismissViewControllerAnimated:completion: method to the view controller you want get back to it will dismiss the modals that are on top of it.
You can also look at using unwind segues. Unwind segues let you go back where you came. Do a search in the Xcode help system on "Using unwind segues" for more information. Most of the tutorials on unwind segues are written in Objective-C but you should be able to find some in Swift if you look. Explaining unwind segues in enough detail to be useful is more than I can cover in this answer.
I'm working on a storyboard-based iPhone app.
I am successfully using unwind segues to navigate my stack of view controllers.
However, when I present a modal view controller I cannot seem to be able to trigger the unwind segue that I have specified in the storyboard file.
Is this normal or a bug?
Problem solved.
Apparently I've hit some glitch with the storyboard editor.
What I did was to delete the destination (modal) view controller and then re-create it.
Works fine, now.
Bug report filed.
So I have the same problem (more than two years later!). I haven't fixed the underlying issue, but I found that a modal view being presented with a default presentation style will unwind OK, but one that uses a page sheet presentation style simply doesn't work. The unwindToViewX method gets called on the parent view controller that the unwind segue is moving to, though, so I've circumvented the issue with the following code:
if (self.presentedViewController) {
[self dismissViewControllerAnimated:YES completion:NULL];
}
This saves me from setting up a delegate system as the unwind action is doing all the heavy lifting, but also avoids an issue where perhaps the unwind action might work one day, because in that case self.presentedViewController should return NO because the unwind action worked correctly and we won't end up dismissing two view controllers by accident.
I hope this helps others in the same boat, but I'd also like to hear if anyone else has better solutions.
I use three view controllers and on each view controller I put UITableView and UITableViewCell. When I connected from the first view controller's table view cell to another view controller's from within storyboard and ran the simulator, the segue works as expected. However, when I connect from the second view controller's table view cell to the last view controller from within storyboard IN THE EXACTLY SAME WAY as the first one, then for some reasons the transition doesn't work.
If I define didSelectRowAtIndexPath: and within it call [self performSegueWithIdentifier:#"showDetail" sender:self]; in the second view controller's implementation file, the transition can work as expected. I don't care about whether it's storyboard segue or methods defined in my code to perform the transition, as long as the transition does work correctly.
However, I'd still like to know why such inconsistency occurs. As I said, I connected two storyboard in the exactly same way in both cases and checked out attribute inspector and connection inspector, but I don't find any differences between the two connection there.
Also, while the first view controller can perform the transition without the method being defined, when I define it then the transition doesn't work, issuing the following error message:
Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
I think I cannot use both approaches (i.e. storyboard segue and method calls) - I just wanted to know what derives the inconsistency here.
I use iOS 7 and Xcode 5.
First of all, if you use push segues, you can't make a push for the second segue if the first segue is modal (unless you embed your second VC in a navigation controller).
Second, make sure de segue identifiers are unique for each segue.
If you ctrl+drag a segue in storyboard, don't call performsegue in code, you just attempt to do the same operation twice. If the segue is in storyboard, in code you should use prepareforsegue delegate.
Another way of doing all of this is not using any segue in storyboard, then in code #didselectrowatindexpath you can instantiate your destination vc using [storyboard instantiateviewcontrolerwithidentifier...], then [self.navigationcontroller pushviewcontroller..] for a push segue or [self presentviewcontroller...] for a modal.
EDIT: Also, when you ctrl+drag, make sure you are dragging from the cell and not from the table.
Self Answer
I finally found out that the issue was not caused in storyboard - it's on the implementation code. Since I have to use UITableViewCellStyleValue1, I cannot use dequeueReusableCellWithIdentifier, and for some reasons the dequeueReusableCellWithIdentifier has to be used in order to make an automatic transition from cell to another view controller from within storyboard only. I checked out that using dequeueReusableCellWithIdentifier and disabling UITableViewCellStyleValue1 temporarily makes it successful to make the transition without didSelectRowAtIndexPath: method being defined.
I'm new to iOS dev and am not entirely sure on Storyboards/Segues/Pushing and Popping.
So in my app I have a navigation controller with 5 view controllers leading from one to another.
When it reaches the last view controller i have a segue to the first and I have a few tasks listed in the prepareForSegue method.
Out of curiosity I decided to check what happens to the [self.navigationController.viewControllers count]. I found that it keeps growing and growing which doesn't 'feel' correct.
Am i handling going back to the first screen correctly? The prepareForSegue method is useful as it allows me to send some data back to the first segue. Is it possible to maybe say when you go back clear all views on that navigation controller?
Thanks
You can use an unwind segue. Here's a good tutorial:
pragmaticstudio.com/blog/2013/2/5/unwind-segues
Make sure to create the unwind action method before you wire it up in the storyboard otherwise it won't show up when you drag to 'Exit'. That was the most confusing part for me when I first set one up. The tutorial does it in the correct order so if you follow it you should be fine.
Also, here's a sample I put together showing how to transfer data back in an unwind segue. It uses a modally presented view controller but the technique is the same:
github.com/soleares/AddToTableView
No, you should never go backwards with a segue (other than an unwind). Segues ALWAYS instantiate new controllers, so you're not actually going back to the first controller, you're just creating a new instance, which gets added to the stack. So either go back with an unwind segue or use popToViewController:animated:. Using an unwind segue will allow you to use prepareForSegue, and it does cause all the controllers in between to be deallocated (if you have no other strong pointers to them).
I created a storyboard for my app which contains the following:
Initial view controller on my storyboard is a Tab Bar Controller (let's call it myTabCtrlr)
myTabCtrlr has forward segues pointing to several other controllers:
a. First segue points to a custom UIViewController (let's call it vc1) on which I create an interactive UIView (let's call it popview1) which is initially hidden. There's a button (let's call it showPopView1) on vc1's view which when clicked would show popview1
b. Second segue points to a navigation controller, which embeds a view controller with 3 buttons, each pointing to an (end) controller.
c. Third segue points to another navigation controller with a similar setup as (b)
On several of these (end) controllers, there's a button similar to vc1's showPopView1 that when tapped, I'd like to switch back to vc1 and programmatically bring up popview1, which I'm doing as follows (but it's not working):
myTabCtrlr.selectedIndex = 0;
//I get a handle to vc1 then
vc1.popview1.hidden = NO;
When I do that, it goes back to the first tab and shows vc1 view (which is good) but it does not show popview1. I tried many different ways to do it but no luck.
Note that if I'm actually on vc1 and I tap the showPopView1 button, then popview1 comes up normally.
Does anybody know why that is the case? This only started after I transitioned to using storyboard. thanks.
After spending hours looking at various ways to solve this problem, and focusing on reverse segues and similar methods, I was able to solve it using a totally different method.. I wanted to share this with others so nobody has to waste so much of their time (although I noticed slow response to my post. Maybe I didn't make the subject attractive enough :)..
It's a really simple solution, but quite effective. I used a Singleton pattern object. When coming from the rest of the tabs, I set a flag in the singleton that vc1 checks in its viewWillAppear method, shows popview1, and immediately resets the flag.. works like a charm!