I have a simple tabbar app. Built directly from the tabbar template. As I test the app, I notice that the app sometimes crash. After pinpointing the right sequence, I found out that the app will crash if I do this:
Run app. Open the view that has a UIPickerView on it.
Open another view.
Tap home button (this will send the app to background).
Tap the app icon again to bring it at the front.
Tap the view that has the UIPickerView in it.
Crash!
Checking the console shows:
-[UIPickerView setFrame:]: invalid height value 130.0 pinned to 162.0
The UIPickerView I use is a custom size. I use transform of scale 0.8f on the height. So if you calculate 0.8*162.0 is indeed 129.9f (130 as mentioned by the console).
I have no idea how to fix this. Any ideas?
The problem is solved. It seems when the app goes to the background, UIPickerView needs to find its components resources again. It is not about sizing of UIPickerView at all.
I used images for the UIPickerView components, so after I populate the UIPickerView with these images, I released all the images that were allocated earlier. These images must not be released if it were to work in iOS4.
Only release them when the app ends.
Your problem has been fixed by another guy with a radical approach. See this post'sanswer provided by a guy named bhavinb.
Related
I have an extra UIView object that I just dragged onto the storyboard. It covers the entire iPhone screen. So I clicked on it and dragged it until it only covered half of the iPhone screen.
This is what my storyboard looks like with my extra UIView object selected:
However, when I actually use the app on my iPhone, the UIView is much smaller and doesn't even take up half of the screen(It's the square with the stackoverflow site image inside of it):
How can I keep it from being smaller when I actually run the app? When running the app, I want the UIView object to be the same size as it is on the storyboard in xcode.
Thanks for the help.
You must have selected Autolayout. Uncheck it and problem is resolved.
I'm developing an Enterprise app for tracking mileage and maintenance for company vehicles. I've added graphic buttons to snazz it up a bit. The buttons look the way they're supposed to look on the XIB in IB, and on the iPhone all other UIViews look correct, but on one particular UIView the graphic images are stretched way out of proportion vertically.
The first image below shows how it's supposed to look, with the three graphics buttons at the bottom. The second image shows how it's showing on the phone. The Help button on this screen cap shows normally, but it can't be counted on to stay that way.
It also is not consistent. Calling this view at any time may show the image stretched or it may not show an image at all. It rarely shows the image normally, like the Help button looks below.
The development phone is a 4S running 6.1.3. The views are set for the Retina 3.5 screen. XCode is the latest (whatever it is).
Again, it's only on this one view that the problem shows up. There is another UIView on the same view controller that is hidden when this UIView is shown. The button graphics on the other view look fine. All of the other views and view controllers use the same graphics on the UIButton, without any problem.
In Interface Builder (Xcode) you created the view using a 4.5-inch screen height.
But the device where you are seeing the problem is a 5-inch screen. So the view is resized to fit.
And when it does that, the autolayout constraints that Interface Builder put on those subviews take over to determine what they do. Those constraints are causing the heights to change.
No need to turn Autolayout off. Autolayout can be very useful, but it seems to enjoy randomly assigning the constraint "Align Baseline to:" to UIButtons after repositioning them.
Just select the UIButton/UIImageView in question inside Storyboard, locate the constraint "Align Baseline to:", tap the gear icon and select "Promote to User Constraint", and tap once more and select "Delete". This should solve your issue.
In response to the comments here, I will answer my own question: I turned Autolayout off for this view controller, and that fixed everything. This is the first app I have written since XCode has begun development for the iPhone 5, so I wasn't aware of the Autolayout feature. I'll need to understand how it works and why it did what it did.
Thanks for all your help!
I often time see in an iOS apps when you first launch the app there will be a one time instruction with arrows and such to show a first time user guide. It's usually a black transparant colored screen with arrows. I was trying to find a few app that does this, but I couldn't. Was wondering if someone knew the terms for these and how to create it?
Create a UIView and place it above the view you're wishing to guide the user through. Set up the UIView as a IBOutlet in your classes header file, set the background to black and set the alpha to 0.3 or something similar (test to see how it looks).
In header:
IBOutlet UIView *overlayView;
In main:
overlayView.alpha = 0.3f;
You may want to make sure that the overlay shows the first time the users opens the app or maybe store a value in a database for when the user dismisses the screen so that you don't show it again. To do this you can hide the UIView or simply set the alpha to 0.
Then simply add images or annotations to the UIView. As "bentford" said it's quite broad but this should get you on your way. You can also use multiple UIView's or even transformations to animate the screens.
I use Skitch. You can find it in the Mac App Store.
Skitch can take the screenshot in the simulator and overlay the arrows and notes. Then when you launch the app, you show the image created with Skitch in a UIImageView on top of the actual view. Then just hide the UIImageView.
I have a tabBar in my application. In one of the section i have two views which i toggle between using segment buttons.
In one of the view i have MapView which i use to display list of users using their pic as annotation. On the other view i have tableView which shows the same users in table format.
Now everything is working fine, i am getting all the users and it displays fine on the map. It works perfectly most of the time on all device and all iOS but sometimes when i bring the mapView to front or toggle or try to zoom in. Both the views (tableView and mapView) just gets removed somehow and i see black screen (which is btw my superview so thats not a problem).
Does anyone know why this happens. It happens frequently on iPhone 3G the older iPhone.
Thanx for any help.
I've had the same problem. I think it's due to low memory to which your app responds by deallocating the tableView and mapView. My solution was to have both views allocated in viewDidLoad. I'm not 100% sure about this, but you could give it a try.
I am working on a photo gallery app. Root view is a navigation controller which takes the user to the thumbnail view. Tapping any thumbnail takes the user to PhotoView which shows the tapped image in full screen.
Below is what I have done in my PhotoViewController:
The approach is pretty much similar to the ScrollingMadness project which I found at github.
I initialize a UIScrollView and add it as a subView to my view controller's view. Set some basic properties of UIScrollView.
Add images to UIImageViews (5 in numbers).
Add all these imageViews as a subview to UIScrollView.
When zoom operation is performed on any image, all the image subviews but the current one are removed from the scroll view.
When the image zooms out back to the minimum scale, all the images are added back to the UIScrollView.
As explained in the sample code from Apple, I am using TapDetectingImageView delegate to create the imageViews and handling touch events.
When I run the app, everything works fine in simulator. No issues whatsoever. But when I run the app in device, it crashes after I scroll to 3rd or 4th image. While debugging I found out that didReceiveMemory warning is called after I scroll to 3rd or 4th image.
I run the app using Instruments. The object allocations shows allocation levels to only 1.5-2MB when the crash happens. I believe memory usage to this level is very normal ... right?
Anyone who experienced this before OR any input as to how I can get rid of it... would be all the help I need in world at this time.
Let me know in case you need any other info.
PS > Its frustrating to see the whole app perfect in simulator but crashing in the device :(
It is crashing because its running out of memory, one thing you should check is the size of the pictures, are you picking the image from the photo library w/o editing, sometimes this will give u images of resolution of 1600x1400 which will pretty much just crash the phone because it runs out of memory, for this you should just resize your images to smaller ones. Another problem that could be causing it is you are loading too many images at once (i dont think so though), if you are using t he scroll view to have a scrolling similar to the photo application on the Iphone then you should only need to load 3 images at a time. Also maybe you arent r eleasing the images properly when you are zooming . I dont know if you a re trying to accomplish a similar functionality to the scrolling of pictures in the photo app on iphone, if you are look at the sample project PageControl, they illustrate that pretty well there.