My iPhone application uses the camera to take pictures, which I suspect is somewhat memory-intensive. The app uses a custom background image for the view of its UINavigationController, and after taking a few pictures, the background goes all white. Any ideas on what I can do to stop this?
Check to see if -didReceiveMemoryWarning is being called in any of your viewControllers. If it's a low memory problem, that's probably the culprit.
Expanding on Ben Gottlieb's post, is it really necessary for you to have the custom background image? That by itself is a big memory waste; I shutter (eh, camera pun) to think of combining the two without releasing the picture before redisplaying the tableView.
Unfortunately, the project was very specific about having a background image, so I had to retain it despite the memory waste.
My work-around was to unload the background once you've entered the photos-view, and then reload it before you leave. Not the most beautiful solution, but it works really well.
I had exactly the same issue, and resolved it by subclassing UINavigationController.
Then in the viewDidLoad method I simply create my background (ImageView) and add it to the view.
If your UINavigationController is created from a nib, just give it your custom class name in IB. I had to do that as I also have a custom navigationbar, which you can only set in IB.
Related
EDIT**: Although someone has decided they would like to down vote without a reason I'm going to leave this up. I noticed that in viewDidLoad of my view controller container, the content view I setup was the same size as in IB. When I later tried to load other views with my view container controller, the content view had changed it's bounds. Hope this helps anyone else that has a similar issue. The excepted answer worked. Since this is a build for iOS 6 a simple check of OS version made this an easy fix.
I have a strange issue that seems to be iOS7 related. This is an iOS6 targeted app. I have followed apples own docs about creating custom container views here. The problem I'm seeing in iOS7 is the first view I load is within the proper bounds of the content view i have defined, the other two are filling the bounds of the entire screen so it hides under the navigation bar with my segmented control. I defined the view I'm loading in a separate view controller in storyboards. Is there some sort of constraint that is working against me?
I should add that I have noticed the content view I defined in my container controller is actually changing it's size after the initial view is loaded. I'm at a loss of how to stop iOS7 from changing that UIViews frame size when it really shouldn't be changing.
Here are some screenshots. Code is pretty much the same as in the apple docs, have tried a few other ideas, defining bounds etc. but I think it has something to do with IB since the content view is changing its bounds. It appears to only be doing so in iOS7.
There is actually a proper way to fix this,
Set edgesForExtendedLayout to UIRectEdgeNone for the view under the tab bar.
Of course, I might've just looked at the pictures and assumed this was your problem...sorry if its completely unrelated..
That's a known 'issue' in iOS 7. Since you can now have a blurred look through the UINavigationBars, UITabBars, ... This also causes issues in native apps (e.g. the Photos App) or APIs.
I have a series of UIImageViews in a UIScrollView. The user can zoom into each one, but after a bit of usage the images start disappearing, and then various images in the app disappear. I'm wondering if anybody has any any experience with this and has any idea why this could be happening?
Its a complete guess until you give us source, but chances are that you are doing something like not retaining your image views or are adding them to another view – effectively removing them from the first view they were in.
I am making my UI from nib files and have added a few animations for UIKit.But as i continue to use my application UI starts to load while animating.Even Navigation bar show with an animation.It seems some kind of memory issue or by some reason uikit is taking time to draw its controls.Would appreciate any kind of help
Here is what i did wrong.I animated a few view using UIView animations but missed to call commitAnimation.I think this is what end up the routine.Thanks for the helps however
You should post some code, but it sounds like you're doing view manipulations inside of a UIView animation block that you shouldn't be doing.
I have a view with a UIScrollView, UIImageView for a background, and a UITextView. I have created several other views just like this and they all come out okay - with a background image and scrollable text but for some reason, now I can't make that work. Either my image overlaps all of the text so that I can't read it or the UITextView default background (white) shows up so that the user can't see the background image. What could be causing this problem?
Do you use Interface Builder or build the views hierarchy in code?
In both cases you should make sure that the order of your views is correct.
In IB the view that you want to appear on top of all the rest has to be under the rest of the views.
In code, make sure that the text view is the last to be added to the hierarchy.
You could also use the next code in order to check if this is the problem:
[self.view bringSubviewToFront:textView];
Okay, it must have had something to do with choosing the delegate. I can't say that I completely understand how I fixed it but it had to do with declaring the delegate in IB.
I have an iPhone app that displays a modal view controller. The modal view controller shows two instances of a custom subclass of UITextView called RoundedTextView, an MKMapView, and a UIToolbar. I construct the viewController only once, and reset its data and present it each time the user summons it.
When showing this view controller with presentModalViewController, I noticed that the animation to show the view was choppy on the 3G. So, to speed it up, I set the alpha of the MKMapView and the two RoundedTextView objects to 0 on viewWillDisappear and back to 1 on viewDidAppear. This made it nice and fast. I also presume that I could remove the views from the superview to speed it up as well.
Does anyone else jump through these kind of hoops on the iPhone. Is there something else I should be doing to avoid this hack?
It's not a hack to simplify drawing during animation in order to make the animation more smooth. It is indeed a very valid technique.
You may be able to achieve similar performance improvements by setting all UI elements to Opaque, a technique also used to fix table view cell performance issues. You just have to make sure background colors match.
The main problem I had was I subclassed UIButton to make gradient buttons and I had the boundary mask enabled. This made the performance terrible. I removed that option and made my buttons square and it's blazin now.