My iPhone app has a tabBar at the bottom.
The 5th tab is rarely used... but pretty memory-intensive... so I want to make it UNLOAD each time it is exited (by the user clicking on a different tab).
But how?
I thought I just needed to call "[self viewDidUnload]" but that doesn't seem to do it.
Where is the "forceThisViewToUnload" and where should I put it?
i think you can call didReceiveMemoryWarning but its bit hacky way :)
just make sure it's not referenced anywhere.
so remomve it from the view-stack, and if you own it, send it a release message.
Related
Recently I have been working on an old swift project built in back in 2015. Its really difficult to find which ViewController is executing currently because of the naming convention, usage of really massive storyboard(I feel terrified to even go to the main.storyboard) and various reason like usage of different language. Of course I can find it but it takes long. I was thinking if there is any way like when I run the project on a device and navigate to different page is there any way to see in the console which ViewController is executing ?
There is a quick way to find what view controller you are on when you are running your app.
1) Launch your app on the device or simulator.
2) Go into Xcode and tap this button:
3) This will open the Debug View Hierarchy. Click on the phone and you will see all the elements in the top bar. You can also see a hierarchy on the left-hand side. In here, you can click down and you will see the name of the view controller on screen.
Using the debugger after putting a breakpoint where you prefer you can write this and press return.
Swift 4.x
po UIApplication.shared.keyWindow?.rootViewController?.value(forKey: "_printHierarchy")
This method is a private API, thus you cannot use on production code, just use it in debug or from the debugger console.
I think it is better to see in debug area for your current viewcontroller named self, you get all information from there open the dropdown and and see you need to put break point in your viewController init method or where you want to debug, However you want to know programatically which is you current viewController you can get it by
appDelegate.window.currentViewController()
If you need which ViewController is Pushed or presented you can get from the above code but the case will be different if you are using the Slidemenu controller, I mean it is totally depends on how you have started navigation and which navigation controller is currently is use.
Can you briefly describe why you need current ViewController so i can help you further.
This is kind of a silly question, but I cannot find the answer as I don't know the terms with which to search for it.
I am looking for a simple way of giving a 'status' message like 'Data updated' to the user without necessarily interrupting what he/she is doing (but have a option I guess in some instances to tab it an perform an action).
For example; some Apps give a rounded square semi-transparent with 'Lock screen/rotation' when an iPhone is rotated, I am look for something similar (or like the square box 'Build Complete in Xcode 4').
Is there an easy way of doing this?
Thanks a million in advance!
https://github.com/myell0w/MTStatusBarOverlay
MTStatusBarOverlay adds very subtle text to the phone's status bar. If you're looking for something a little more noticiable, try:
https://github.com/jdg/MBProgressHUD
As #kubi has pointed out, MTStatusBarOverlay is a good one, and I've passed Apple reviewer inspection with it. However I just found something that looks fraking awesome...
Tweetbot-Like Alert Panels (Blog), and the repository is MKInfoPanelDemo at Github.
Create a view that shows your message nicely, add it to the window, and start a UIView animation which makes it fade away. In the animation ended handler (delegate or block) remove the view.
I have an iphone app with a modal view. The app crashes when the modal view get dismissed.
As soon as the modal disappear at the bottom of the screen, and consequently the original view is shown behind, then the app crashes with no entry in console view.
I have tried to switch debugger on and I discovered that the app just run fine, with no crashes at all.
-First, I would like to know why such behaviour, shouldn't the debugger sit just on top without "disturbing" the app ?
-Second, without debugger, can you point out what should I look at to solve my problem ? Or if you encounter something similiar ? Please be as much specific you can, because I am not an expert in objective-c programming.
I don't know what details to give you, the app is a normal one with standard iphone component, but for start I can say the modal view (which is built with IB) is called inside a NavigationBar system.
thanks
When these types of things happen, it is almost always because of memory allocation issues. The first step I would take is to do a "Clean All" and a "Build and Analyze", and look at all the analysis warnings. Analyze is very good at finding basic "use before allocate", "use after deallocate", or "wrong number of retains/releases" types of problems.
The next step is to turn on "Zombie" detection mode, which looks for accesses on memory that has already been deleted (in other words, killed objects coming back from the dead.) To do this, get info on your executable, go to the Arguments tab, and add a "variable to be set in the environment" of "NSZombieEnabled" to value "YES". Then look in the console when you run to see if something looks off.
Finally, you might try creating a new configuration where you use all the release mode settings for optimization, but add debug symbols. Maybe that will shake up the allocation disbursement in memory enough to trigger the bug in debug mode.
I am having much difficulty being able to dismiss (programmatically) my UIDocumentInteractionController's OpenIn Menu (Using the appropriate - dismissMenuWhatever method from the docs). I just can't seem to get it to work. Does anybody have any suggestions? Maybe I have an inadequate intelligence level? I am beginning to question the meaning of life.
make sure you are calling dimissMenuAnimated: on the right UIDocumentInteractionController. Maybe post some code if you still can't figure it out.
I am close to finishing my first application (a UITableView style one) on the iphone but have realised it will look much better, and stand a far better chance of getting through the approval process, if it is presented as a navigation-based app rather than a view-based one - in hindsight my initial choice is not really suitable...
Is it possible for me to somehow change easily the application into a new type, or would i be better starting again from scratch with all the hassle that would entail...
thanks for any advice on how it may be done,
karl
It wouldn't be particularly difficult to shift the means of interaction to a navigation controller from a simple view controller (it also isn't difficult to go the reverse direction). Although, there isn't anything as simple as a tutorial on how to do it or menu item you can select. You could look at the plumbing generated by Apple's template for a navigation based application and add the necessary glue to your app delegate. Once that is in place you could simply push your view based applications view controller onto the navigation stack. If you have more specific questions or are stuck somewhere in particular we can help to get you un-stuck if you provide details about where you are running into issues.
As an aside, I doubt your application will be rejected solely for being view based vs. navigation based.
Hmmmmm, for soem reason t wont let me add anything to comment on your post!
Anyway, i guess this is as good as anything here...
Ive been messing for the last hour or so and have managed to integrate my old code/data etc into a new navigation one without too many problems, in fact it looks nicer with a title bar at the top!
(I do like to try and work stuff out for myself so its a good learning curve!)
I am still struggling in that although the new view opens up i am
struggling to use a string from the first view (I have a UITableview table in there, i select a row and get a correct value from it which i currently check via an alert message) in the second view.
for some reason i do not get a title bar and 'back' button in the 2nd view so i guess it is not being put on the stack correctly (I have put a quick 'return' button in the view for testing purposes so i can navigate backwards and forwards).
Still, Im about 100% further on than i was earlier!
cheers for the reply,
Karl