Im trying to return to a specific ViewController in it's current state after going from that ViewController to another using presentViewController.
But when I try to close the other ViewController (with dismissViewController) I get a white screen.
RootViewController *rootViewController
= [[UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil]
instantiateViewControllerWithIdentifier:#"RootViewController"];
[self presentViewController:rootViewController animated:YES completion:nil];
This isn't an option either because that instantiates a new viewcontroller and I want the old ViewController in its current state.
Do I need to pass the RootViewController as an argument when presenting the other ViewController or is there another option to return to the RootViewController in its current state?
Yes, there is a way to return original screen.
I met just like problem but solved it with following code line
[self dismissViewControllerAnimated:YES completion:nil];
one way to address this is to avoid having one view controller responsible for presenting and dismissing the other one.. what you can do is create a controller of controllers (give it a singelton method).. and have that object basically keep a reference to any view controller you are interested in maintaining its state. That way you wouldn't have worry about what's going on behind the scenes when you dismiss or present a view controller.
Related
After a viewcontroller has been presented modally, the initial preferredfocusedview is called. However, after we dismiss the viewcontroller and it has been dealloc. preferredfocusedview is not called after presenting the viewcontroller again. Running on tvOS 9.2.
Even adding the following did not help:
-(void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[self setNeedsFocusUpdate];
[self updateFocusIfNeeded];
}
Anyone know what's going on? Or if there's anyways to debug this?
Edit:
the way I am adding the viewcontroller:
viewController = [[UIViewController alloc] init];
[viewController addChildViewController:self];
[viewController.view addSubview:self.view];
[self didMoveToParentViewController:viewController];
If you are using a container view, having multiple ViewControllers or adding only one View Controller, the preferredFocusEnvironments method must be called from the rootView Controller indicating which View Controller to focus.
For eg.
View Controller A has a container View having ViewControllers B and ViewController C inside the Container.
View Controller A should have preferredFocusEnvironments returning which ViewController to focus.
This way, preferredFocusEnvironments on ViewController B or ViewController C will be called whenever the view becomes visible.
If the ViewController A doesn't have preferredFocusEnvironments, then it won't be called on the containerView ViewControllers.
Implementing custom focus behavior in tvOS 9 is disaster. Apple already mentioned that there is a limitation on redirecting focus specially when presenting/ dismissing a viewcontroller in WWDC.
tvOS10 will handle munch better with preferredFocusEnvironments.
https://developer.apple.com/videos/play/wwdc2016/215/
When I needed to fix this focus redirection issues in viewDidAppear in tvOS 9, I had exactly same issues. Sometimes it works, sometimes not. No clue what so ever. But after I put split second delay on setNeedsFocusUpdate / updateFocusIfNeeded in viewDidAppear it was way better in terms of consistency. preferredFocusedView get called all the time.
-(void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self setNeedsFocusUpdate];
[self updateFocusIfNeeded];
});
}
Do this in both presented and presenting view controllers, if you are manually changing focus. This is all from my observation and I don't think there is a proper way to achieve some focus behavior because tvOS API is kind of new and premature. Sorry about not being able to give you good explanation why this might work. Good luck.
I have a UIViewController in a storyboard iPhone app that I need to reuse in several places. In the storyboard, there is a UIBarButtonItem that has a triggered segue to another controller. In some cases, however, I would like to override the behavior of the button to segue to a different view controller. I'm thinking that there must be a way to either initialize the view controller with a message that specifies the target view controller, or to set some property after the controller is initialized but before it's pushed?
One challenge seems to be that segues can't be defined programmatically (based on what I've read so far), and I don't think I can have multiple segues on the same view controller in storyboard. So I may need to do something like this:
[self presentModalViewController:myNewVC animated:YES];
... rather than use a segue, but I'm not sure how to override the behavior of the button defined in storyboard to do it that way.
Any help is appreciated.
Just create an IBAction and a BOOL for some condition to pick which view controller should be instantiated.
UIViewController *viewController;
if (someCondition) {
viewController = [self.storyboard instantiateViewControllerWithIdentifier:#"someViewID"];
}else{
viewController = [self.storyboard instantiateViewControllerWithIdentifier:#"someOtherID"];
}
[self presentViewController:viewController animated:YES completion:nil];
I'm having problem with accessing my tabbarcontroller in the storyboard when its not the initial view. So basically there is an initial view in the storyboard which leads to the tabbarcontroller. I want to change the color of the tab but i dont have access to it! I know that it can be added to the delegate if its the initial view but in this case its not the initial view in the storyboard! I read somewhere that I have to override a method in the first view but there was no detail about it!
If you are in a viewcontroller in the storyboard then this code:
UIStoryboard *storyboard = self.storyboard;
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:#"OtherViewController"];
Will get the other viewcontroller youw want and you could do things such as:
set yourself as delegate for it:
[(OtherViewController *)vc setDelegate:self];
display it:
[self presentViewController:vc animated:YES completion:nil];
I think you could use this to get the other viewcontroller and then access the tabbar from it.
Sorry if I misunderstood what you are trying to do.
I make a program that shows a table.
If people click the search I will add another view covering the original view. The original view is [BNUtilitiesQuick listnewcontroller];
[[BNUtilitiesQuick window] addSubview:[BNUtilitiesQuick searchController].view];
[[BNUtilitiesQuick searchController] viewWillAppear:YES] is indeed called. So it seems that UIView has a pointer to it's controller
However, the view that the [[BNUtilitiesQuick listnewcontroller] viewWillDisappear] is not called
Moreover, [[BNUtilitiesQuick listnewcontroller] viewWillAppear] is also not called even when the user has finished modifying search term with this code:
[self.view removeFromSuperview];
I think I may be missing something here. What exactly should I do anyway so IOs knows that the searchController.view will be covering listNewController?
This is NOT the right way to do it. If the searchController is a full screen controller you should present it modally using presentViewController or push it onto the navigation stack as #StuR suggested.
In case your search view covers only part of the listnewcontroller you should use the containment API in iOS5.
Inside listnewcontroller (parent view controller) you would write:
[self addChildViewController:self.searchController];
[self.view addSubview:self.searchController.view];
[self.searchController didMoveToParentViewController:self];
For more in-depth information check out the WWDC 2011 session video "Implementing UIViewController Containment". Also watch "The Evolution of View Controllers on iOS" from 2012 because there are some changes and deprecations in iOS6.
ViewController *viewController = [[ViewController alloc] init];
[self.navigationController pushViewController:viewController animated:YES];
I'd consider using pushViewController for adding a full screen view. addSubview is for views that don't cover the entire screen.
viewWillDisappear and viewWillAppear will only me called if you pop or push the given viewController. You are simple adding a subview with it's own viewController inside(on top) of the present viewController. As StuR said, if you want to dismiss the current ViewController you should use:
BNUtilitiesQuick *searchController = [BNUtilitiesQuick alloc] init];
[self.navigationController pushViewController:searchController animated:YES];
You can read more about ViewControllers here: http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007457
I have 2 ViewControllers directly connected with a push segue. I am navigating from first to second view controller by calling [self performSegueWithIdentifier:#"segueIdentifier" sender:sender]. On the second one I have an IBAction method that is bound to a "Done" button. Pressing that button should basically cause the first view controller to be displayed (sort of a back button). I managed to do that with:
NSArray *viewControllers = self.navigationController.viewControllers;
[self.navigationController popToViewController:[viewControllers
objectAtIndex:0] animated:YES];
I did try to achieve the same effect by using:
[self dismissViewControllerAnimated:YES completion:nil];
No matter what I tried though this didn't do the job. I am trying to understand what exactly am I missing but I can't figure it out. Does dismissViewControllerAnimated method work only with Modal segues ( this is the only thing that came to mind ).
Thank you
Yes,
- (void)dismissViewControllerAnimated:(BOOL)flag completion:(void (^)(void))completion
is when a UIViewController is displayed modally.
- (UIViewController *)popViewControllerAnimated:(BOOL)animated
should do what you are seeking.
So basically, in your second VC:
[self.navigationController popViewControllerAnimated:YES];
You will save you a lot of trouble if you read the UIViewController and UINavigationController references. Twice ;)