In simulator, app is blank (white), but appears normal when quit? - iphone

So I'm new to programming but I'm managed to create the groundwork for an iPhone app.
Problem is, when I run it on the iPhone simulator, it first shows up as a white/blank screen (with the status bar at the top) until I hit the home button. When it is doing the minimization animation (~0.5 second) the app will display correctly.
I know that an issue with versions could be the cause of this but I'd need to buy a newer Mac to upgrade to the latest version of Xcode. If there are other issues that could be causing this I'd love to know
thanks :)

Add Default.png image to your application and see if it shows that during loading. Run the app in debugger and add a breakpoint to viewDidAppear in your viewController. It's probably running but not loading in the view you are expecting it to for some reason.

To some viewcontroller's view your are not setting the background color as clear color .. that's why it is showing blank white screen when your application is launching .. if your are using xib .. set the background color of that view to clear color using interface builder.

Related

Black screen instead of launch image on iPad

I am developing an iPhone app for iOS 6.1 and 7 (using Xcode 5). I have a problem with iPad launch images.
On iPad 7.0 and 7.0.2, the launch image is not showing up(in 6.1 works!): I get black screen while app is loading.
I don't face this issue with iPhone 6.1 and 7.0.2, although I set all launch images required for iPad and iPad retina (landscape and portrait) and I use Asset Catalog.
What am I missing?
Recently I faced same issue with my App designed only for iPhone , I had the problem where the launch images would not appear in iPad (On iPad ios >= 7.0.x the launch image is not showing up I get black screen while app is loading (in iPad ios < 7.0.x it works fine )).
I don't face this issue of launch image with iPhone worked fine in all iOS versions.
Solution: Is to update to asset catalog to manage your app's images and target only iOS 6 and Prior.
Steps :
Step 1:
Step 2:
Step 3: on the top right corner click on the 'Attribute Inspector' icon. Here you can set the Target OS for the Launch Images.
Uncheck the iOS 7 check boxes for iPhone, Now you should be able to see the launch images for iPad on iOS >= 7.0.x.
If you have the same situation like mine, that's solution:
My app is landscape only, iOs7 only, ipad\iphone (XCode 5).
Problem: black launch on iphone (and simulator), normal launch in ipad.
Solution: go to Images.xcassets - Launch Images - select it. Uncheck at right all "iOs7 and later" boxes. Check "iOs6 and prior" boxes and fill empty spaces with images.
Strange, but works.
Per Apple's documentation (link); an empty iPad specific storyboard may be the answer. I've also seen issues where the initial view controller is not set within a storyboard causes a black screen. A variant of this issue might be an incorrect setting in the app plist.
Technical Q&A QA1780
Why does my app launch to a black screen on iPad?
Q: Why does my app launch to a black screen on iPad?
A: Apps that have been designed only for iPhone may launch to a blank screen when run on an iPad. This is caused by the presence of an empty iPad specific storyboard in the app bundle as well as an iPad specific UIMainStoryboardFile key in the app's Information Property List (Info.plist) file. Both are automatically created by the various Xcode template projects if the Universal option is selected.
...
In Xcode
Look for a file named MainStoryboard_iPad.storyboard in the file navigator. If this file is present, remove it from your project.
In your app's Information Property List
Look for a key named Main storyboard file base name (iPad) or UIMainStoryboardFile~ipad. If this key is present, remove it. You should also remove any other key suffixed with (iPad) or ~ipad.
Finally, test your app on an iPad or in the iPad simulator and verify that it behaves as expected.
I requested Apple support and it turned out that it's a bug. They asked me to report it and I did. Here is the report id : 15340531.
Now it's up to them.
Using LaunchScreen.storyboard
I was having a similar problem until I found the following settings in the General Project Settings.
Set your Main Interface to your main storyboard file. Mine is called Main.storyboard.
Set your Launch Screen File to your launch screen storyboard file. Mine is called LaunchScreen.storyboard. (This is what I had originally ommited.)
After that the launch screen loaded first and then the main story board loaded shortly later.
Try set the image again make sure that resolution of the splash screen is according to the iOS 7 guidelines
I know this sounds stupid. I've had bugs like that when I saved a file in psd-format with a jpg extension. Just 1 wrong click while saving your launch image.
After having tried several solutions found here, I suspected that the iPhone was trying to launch in Landscape orientation, and thus not finding any corresponding launch image. Indeed, the simulator was starting in Landscape for a reason I was not understanding.
Finally, after reading Apple documentation, I found that it's probably the order of keys in "Supported interface orientations" of the info.plist file that was not adequate. The Portrait was the last item. When it's the first item, the app launch in Portrait mode and find the image.
Remove previously installed app from the device or simulator, Then relaunch the app after clean.
I had the problem where the launch images would no appear in iPhone (3.5 or 4 inch) in iOS 7, but the iPad had no problems with iOS 7.
Long story short is I disabled the asset catalog for the launch images only. So I'm adding the launch images the old fashioned way. That seems to have solved the problem.
I will have to do more testing tomorrow, but it seems the problem is solved (at least in my case).
in Xcode 5 , make sure thay you add all needed images mentioned in your app target.
I am assuming that when you are using Asset Catalog, you have ensured that you have the Images.xcassets target membership added correctly. I am mentioning this since if you have multiple targets, looks like you have to add them manually (and you have not provided any screenshots so one can be sure).
Now that you have not really provided a screenshot of the "LaunchImage" overview of Images.xcassets folder in your project, I can only guess the probable reason. Looking at the fact that the launch images work fine for iPhone (6.1 & 7.0.2 and iPad (6.1) and do not work only for iPad (7.0 and upwards), I think you could perhaps look at as to whether the dimension of the images for iPad Portrait and iPad Landscape are proper for iOS7. Specifically, you should see your launch images and not empty rectangles as seen in the attached pic-
This can happen due to the fact that you still have the iPad launch images for iOS7 created excluding the status bar area. Prior to iOS7, the iPad launch images were created to exclude the status bar area, but it's a must on iOS7 that all the launch images must include the status bar area. Please go through the section "Things Every App Must Do" in Apple iOS7 UI transition Guide (https://developer.apple.com/library/ios/documentation/userexperience/conceptual/TransitionGuide/TransitionGuide.pdf).
The following screenshot should explain what I am talking about-
e.g. you can see that iPad Landscape Retina image dimension for iOS6.1 and previous is 2048x1496 (excluding 40 px for status bar) but the dimension for the same image for iOS7.0 and upwards is expected to be 2048x1536 (including the 40px for status bar). So, if you have not changed your images accordingly, you will see black screen for images on iPad 7.0 and upwards. On iPhones, you will not face this issue since iPhone launch images always cover the status bar, be it iOS6.0 and iOS7.0- so the new UI requirement is already met for iPhone launch images.
I found this answer which worked for our app (iPhone only, but used on iPad): https://stackoverflow.com/a/19448782/1258419
To summarize from that answer:
How to do it. Go to the asset catalog. And on the top right corner click on the 'Attribute Inspector' icon. Here you can set the Target OS for the Launch Images. Uncheck the iOS 7 check boxes for iPhone. Now you should be able to see the launch images for these devices.
I encountered a similar problem in landscape, my iOS 7 launch image wasn’t displayed while the iOS 6 did. Mine was the iPhone Retina 3.5” launch image.
Since I have another app in portrait that didn’t share this issue, I did 2 things:
In info.plist, under “Supported interface orientations”, I added the
2 portrait modes as well, and put them before the landscape, like
this:
Item 0: Portrait (top home button)
Item 1: Portrait (bottom home button)
Item 2: Landscape (right home button)
Item 3: Landscape (left home button)
Implemented this method in the View Controller:
-(NSUInteger)supportedInterfaceOrientations{
return UIInterfaceOrientationMaskLandscape;
}
This works with or without the Asset Catalog.
This is an update for iOS 8.
I got the same problem when I tried to add a LaunchImage to my iOS 8 app.
Apple enables developers to use a xib, whose default name is LaunchScreen.xib, to render the launch view as of iOS 8. I believe developers can use either LaunchImage or LaunchScreen.xib. Unfortunately, I couldn't find any document describing how to deal with LaunchImage after LaunchScreen.xib was introduced. I always got a black screen when I tried to use LaunchImage as the launch view.
My solution is:
Don't think about LaunchImage. Use LaunchScreen.xib. (You have to keep an empty LaunchImage in your Asset Catalog though. I believe it's a bug.)
Drag an UIImageView to the xib and make the UIImageView full screen. Remember to take the size classes and constraints into account.
Set an image whose resolution is enough for iPhone 6 plus to the UIImageView.
Check your all images and see if it is properly placed in the Asset and properly named and sized.
Also check which orientations your are allowing and accordingly add images to the asset.
I had the same problem.
I had to make a workaround: used the Default image for all iOS versions and DELETED the UILaunchImageFile key from info.plist.
I cannot use different launch images for iOS 7 and previous versions, so, I had to use the same "artistic" image for all, instead an image that mimic the first view of the app (which Apple recommends and I prefer), but at least I do not get the black screen anymore.
It looks like the UILaunchImageFile key that allows to use differents launch images for iOS 7 and previous versions is not working properly for Retina iPad in iOS 7.
WARNING: I am still testing the app, so I don't know if could be some side effects.
I also faced the similar issue but its solution was simple (in my case).
All I did was following -
1.Add a new file (if you have not added it) Launchscreen.storyboard
2.Get a UIViewController, mark it as Is Initial View Controller then add a UIImageView in it and set a picture which you want to display during launch of your app. Make sure you give this UIImageView required constraint.
3.Go to Project->General->App Icons and Launch images and select Launchscreen.storyboard as Launch Screen File (There will be a dropdown for it).
Because of iOS 13 and later, app launch different than earlier versions.
Get the solution from below URL.
https://stackoverflow.com/a/59913274/883505
I simply forgot to call super.loadView() in my view controller...
override func loadView() {
super.loadView()
}

how to change the background of an iphone app when it launches?

Everything is in the title but I have to make myself clear :
I don't mean : how to automatically change the background of the app once it has finished launching.
What I mean is : when you first launch the app, before the first view is loaded by the iphone there is a black screen. Is it possible to change this black screen which I get when waiting for the first view to appear? I'd like to put a picture instead.
Thanks!
John
You need to set a Default.png and a Default#2x.png (for retina) and all the work is done for you. Or if you have payed to be a developer, download xcode 4 gm, and you can double click on the loading screen area and you can have it named what ever you wanted.
Just add a picture called "Default.png" to the project (size of the iPhone screen) and it'll automatically appear.
You can add Default.png and it's variations to your project. This image will be displayed as splash screen during application startup (before the first view is loaded).
Search for Application Launch Images at ...
http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/BuildTimeConfiguration/BuildTimeConfiguration.html
You must specify Launch image
http://developer.apple.com/library/ios/#documentation/General/Reference/InfoPlistKeyReference/Articles/iPhoneOSKeys.html%23//apple_ref/doc/uid/TP40009252-SW9
The docs here explain the different types of launch images can should use:
http://developer.apple.com/library/ios/documentation/iphone/conceptual/iphoneosprogrammingguide/BuildTimeConfiguration/BuildTimeConfiguration.html#//apple_ref/doc/uid/TP40007072-CH7-SW12

Iphone OS 3.1 vs 3.2 plus UIView background image display issue

I have a Navigation controller in my app that pushes my homeview on load. The Home View has a subView which actually has the content (I plan to put another iAdBannerView later). The contentView(SubView) has a background image which is aligned with some text/label on the view to give a better look. Everything displays correctly in simulator (3.2 and higher versions).
I installed this in a 3.1 iphone device last night and it looks like the background image gets cut off from the top. It is almost like the view started at the correct position (after navigation bar) but the background image started from the top.
There is unfortunately no simulator for iOS 3.1 so I'm not able to reproduce this anywhere except the device. Even if I could reproduce, i'm not sure how to fix this because everything seems to be set up correctly. Is it a bug in 3.1. If anyone has experienced anything like this, could you please share?
Not sure what really happened. but I was able to change the height property of the content view to 520 or so and it started working fine.

iPhone - Objective C, on app launch image

I'm using the Utility Application template to build my app.
Having a hard time getting an image to show up as the app launch. (I'm having this difficulty with all the templates basically)
Basically, right now when the app launch, it starts with a black background and it takes a second or 2 before the content appears.
However, I see that some apps has an image as it opens up. How do they do that?
I tried adding it to the "UIWindow" and have it set to "visible at launch". It doesn't quite work as expected. (i.e I think it goes behind the views since it is visible only when the views are flipping)
Thank you,
Tee
You need to add Default.png image to your resources directory. That should do the trick.

i image does not work good in utility app on iPhone app

I working on a utility app. When I run the app in simulator clicking i image at the bottom flips the view in a flash. But when I run the app on iPhone device it behaves abnormally. At times it flips the view in just 1 tap. The other times it does not bother to react even after tapping the image 10 times. I tried with other utility app also - same issue. Thus its not an issue with the code I believe.
Any help to resolve this issue is much appreciated.
Thanks,
AJ
This is a problem because the 'i' button is not very big by default and touches are missed easily.
You need to put another button in front of the 'i' button with the 'Custom' type in Interface Builder, so that it doesn't have any image. Then you can make this invisible button much larger and connect it to the same action as the info button.
You also need to enable "shows touch on highlight" in Interface Builder so that you get the white glow effect when the invisible button is touched.