ios8 interview questions
Top ios8 frequently asked interview questions
My app that worked fine on iOS 7 doesn't work with the iOS 8 SDK.
CLLocationManager doesn't return a location, and I don't see my app under Settings -> Location Services either. I did a Google search on the issue, but nothing came up. What could be wrong?
Source: (StackOverflow)
I ran the following code in both iOS 7 and iOS 8:
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
BOOL landscape = (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight);
NSLog(@"Currently landscape: %@, width: %.2f, height: %.2f",
(landscape ? @"Yes" : @"No"),
[[UIScreen mainScreen] bounds].size.width,
[[UIScreen mainScreen] bounds].size.height);
The following is the result from iOS 8:
Currently landscape: No, width: 320.00, height: 568.00
Currently landscape: Yes, width: 568.00, height: 320.00
Comparing to the result in iOS 7:
Currently landscape: No, width: 320.00, height: 568.00
Currently landscape: Yes, width: 320.00, height: 568.00
Is there any documentation specifying this change? Or is it a temporary bug in iOS 8 APIs?
Source: (StackOverflow)
I am currently testing my app with XCode 6 (Beta 6). UIActivityViewController works fine with iPhone devices and simulators but crashes with iPad simulators and devices (iOS 8) with following logs
Terminating app due to uncaught exception 'NSGenericException', reason: 'UIPopoverPresentationController (<_UIAlertControllerActionSheetRegularPresentationController: 0x7fc7a874bd90>) should have a non-nil sourceView or barButtonItem set before the presentation occurs.'
I am using following code for iPhone and iPad for both iOS 7 as well as 8
NSData *myData = [NSData dataWithContentsOfFile:_filename];
NSArray *activityItems = [NSArray arrayWithObjects:myData, nil];
UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:nil applicationActivities:nil];
activityViewController.excludedActivityTypes = @[UIActivityTypeCopyToPasteboard];
[self presentViewController:activityViewController animated:YES completion:nil];
I am getting a similar crash in of one my other app as well. Can you please guide me ? has anything changed with UIActivityViewController in iOS 8? I checked but i did not find anything on this
Source: (StackOverflow)
I have an app where the UITableView's separator inset is set to custom values - Right 0, Left 0. This works perfectly in iOS 7.x, however in iOS 8.0 I see that the separator inset is set to the default of 15 on the right. Even though in the xib files it set to 0, it still shows up incorrectly.
How do I remove the UITableViewCell separator margins?
Source: (StackOverflow)
In iOS 8 i am having problem capturing images from camera till now i am using this code for
UIImagePickerController *controller=[[UIImagePickerController alloc] init];
controller.videoQuality=UIImagePickerControllerQualityTypeMedium;
controller.delegate=(id)self;
controller.sourceType=UIImagePickerControllerSourceTypeCamera;
[self presentViewController:controller animated:YES completion:nil];
But in iOS 8 i am getting this
Snapshotting a view that has not been rendered results in an empty snapshot. Ensure your view has been rendered at least once before snapshotting or snapshot after screen updates.
I have tried with the solution provided by This Post with
@property (strong,nonatomic)UIImagePickerController *controller;
_controller=[[UIImagePickerController alloc] init];
_controller.videoQuality=UIImagePickerControllerQualityTypeMedium;
_controller.delegate=(id)self;
_controller.sourceType=UIImagePickerControllerSourceTypeCamera;
_[self presentViewController:controller animated:YES completion:nil];
and this
...
controller.modalPresentationStyle=UIModalPresentationFullScreen;
or
controller.modalPresentationStyle=UIModalPresentationCurrentContext;
...
and this
double delayInSeconds = 0.1;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[self presentViewController:controller animated:YES completion:nil];
});
and this
[self presentViewController:controller animated:YES completion:NULL];
and this
[self presentViewController:controller animated:YES completion:^{
}];
any idea?
Source: (StackOverflow)
How can I get the Device Token for remote notification in iOS 8?
I used the method didRegisterForRemoteNotificationsWithDeviceToken in AppDelegate in iOS < 8, and it returned the device token. But in iOS 8, it does not.
Source: (StackOverflow)
I have an application which works fine on Xcode6-Beta1 and Xcode6-Beta2 with both iOS7 and iOS8. But with Xcode6-Beta3, Beta4, Beta5 I'm facing network issues with iOS8 but everything works fine on iOS7. I get the error "The network connection was lost.". The error is as follows:
Error: Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." UserInfo=0x7ba8e5b0 {NSErrorFailingURLStringKey=, _kCFStreamErrorCodeKey=57, NSErrorFailingURLKey=, NSLocalizedDescription=The network connection was lost., _kCFStreamErrorDomainKey=1, NSUnderlyingError=0x7a6957e0 "The network connection was lost."}
I use AFNetworking 2.x and the following code snippet to make the network call:
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager setSecurityPolicy:policy];
manager.requestSerializer = [AFHTTPRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];
[manager POST:<example-url>
parameters:<parameteres>
success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(@“Success: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error: %@", error);
}];
I tried NSURLSession but still receive the same error.
Source: (StackOverflow)
When trying to register for push notifications under iOS 8.x:
application.registerForRemoteNotificationTypes(UIRemoteNotificationType.Alert | UIRemoteNotificationType.Badge | UIRemoteNotificationType.Sound)
I get the following error:
registerForRemoteNotificationTypes: is not supported in iOS 8.0 and later.
Any ideas what is the new way of doing it? It does work when I run this Swift app on iOS 7.x.
EDIT
On iOS 7.x when I include the conditional code I get (either SystemVersion conditional or #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 80000)
dyld: Symbol not found: _OBJC_CLASS_$_UIUserNotificationSettings
Source: (StackOverflow)
I want to get a simple launch screen to show in my app, built using Xcode 6.0.1.
I have added a launch screen in two ways: As an XIB (with the default name, LaunchScreen.xib) and as a launchimage set within xcassets.
I have made sure that my "Launch Screen File" is set to LaunchScreen.xib.
I have simulated every device available (e.g., "iPhone5 iOS8" / "iPhone5s iOS8" / "iPhone6 iOS8". Note that only iOS 8 is available within the simulator).
Source: (StackOverflow)
I have a UITextField Ctrl-dragged as an @Outlet in my .swift class.
Now in viewDidLoad i'm using this code
self.myTextField.keyboardType = UIKeyboardType.DecimalPad
When i launch my app on simulator and click on the UITextField i got this log
Can't find keyplane that supports type 8 for keyboard
iPhone-Portrait-DecimalPad;
using 2617181025_Portrait_iPhone-Simple-Pad_Default
I have no crash or something but the keyboard is not displayed. I also tried to set it from Storyboard but it's the same.
I also noticed that whenever i click on any UITextField the keyboard is never displayed (but no log is shown for the default keyboard)
I'm using Xcode-Beta 3 anyone faced this issue?
Source: (StackOverflow)
I'm learning Swift for iOS 8 / OSX 10.10 by following this tutorial, and the term "unwrapped value" is used several times, as in this paragraph (under Objects and Class):
When working with optional values, you can write ? before operations
like methods, properties, and subscripting. If the value before the ?
is nil, everything after the ? is ignored and the value of the whole
expression is nil. Otherwise, the optional value is unwrapped, and
everything after the ? acts on the unwrapped value. In both cases, the
value of the whole expression is an optional value.
let optionalSquare: Square? = Square(sideLength: 2.5, name: "optional square")
let sideLength = optionalSquare?.sideLength
I don't get it, and searched on the web without luck.
What does this means?
Edit
From Cezary's answer, there's a slight difference between the output of the original code and the final solution (tested on playground) :
Original code
Cezary's solution
The superclass' properties are shown in the output in the second case, while there's an empty object in the first case.
Isn't the result supposed to be identical in both case?
Related Q&A : What is an optional value in Swift?
Source: (StackOverflow)
this may sound real NOOB! I want to check if it's the second time the user enters my application, so to keep the run count I'm using NSUserDefaults. I have implemented the following code in my rootViewController's viewDidLoad method:
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSLog(@"hello %ld", (long)[userDefaults integerForKey:@"runCount"]);
if ([userDefaults integerForKey:@"runCount"] != 1) {
//not the 2nd run
[userDefaults setInteger:1 forKey:@"runCount"];
NSLog(@"not 2nd run");
} else {
//second run or more
NSLog(@"2nd run");
}
[userDefaults synchronize];
everything works fine, but the problem is that when I uninstall(delete and re-install) the application according to here and here the data should be cleared, but it is not and after re-installing the app previous data is still showing up.
I'm running my app on iOS simulator using xCode6-beta and targeting the application on iOS 8
Source: (StackOverflow)
I am using a Universal Storyboard in Xcode 6, targeting iOS 7 and above. I've implemented a UISplitViewController which is now natively supported on iPhone running iOS 8, and Xcode will automatically backport it for iOS 7. It's working really well, except when you launch the app on iPhone in portrait running iOS 8, the split view's detail view controller is displayed when I expected to first see the master view controller. I believed this was a bug with iOS 8 because when you run the app on iOS 7, it correctly shows the master view controller. But iOS 8 is now GM and this is still occurring. How can I set it up so that when the split view controller is going to be collapsed (only one view controller displayed on screen), when the split view controller is displayed it shows the master view controller not the detail?
I've created this split view controller in Interface Builder. The split view controller is the first view controller within a tab bar controller. Both the master and the detail VCs are navigation controllers with table view controllers embedded inside.
Source: (StackOverflow)
Xcode 6 interface builder by default has new checkbox "use size classes". It makes views adaptive.
When I try to make segue between 2 views in my storyboard I have new options:
instead old:
Now we have "show" and "present modally" instead of "push" and "modal". The old options are marked as deprecated. I've chosen "show" option, because in segue settings it called "show (e.g. push)
But it doesn't make push. Segue animation looks like slide from the bottom (modal) and navigation bar disappears.
Question is: How can I make "show" work like push? Is it possible or should I use "push (deprecated)" instead? Where can I find any information about new types of segue? The only thing that I've found in iOS8 developer library is Storyboards Help You Design Your User Interface but there is no information about "show" segue.
UPDATE
I tried to create new project and "show" is really works like "push".
I think the issue in my project can be because I reuse navigation controller with code like this, but I don't know how to fix it.
if ( [segue isKindOfClass: [SWRevealViewControllerSegue class]] ) {
SWRevealViewControllerSegue *swSegue = (SWRevealViewControllerSegue*) segue;
swSegue.performBlock = ^(SWRevealViewControllerSegue* rvc_segue, UIViewController* svc, UIViewController* dvc) {
UINavigationController* navController = (UINavigationController*)self.revealViewController.frontViewController;
[navController setViewControllers: @[dvc] animated: NO ];
[self.revealViewController setFrontViewPosition: FrontViewPositionLeft animated: YES];
};
}
After that I try to push NewViewController after MainViewController
UPDATE 2:
I seems to be only iOS 7, iOS 7.1 issue.
Source: (StackOverflow)