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How do I make my App run an NSTimer in the background?

I’m making a benchmark App for test purposes ONLY. I am not intending this to go to the App Store. What I need is my NSTimer to continue running on the background using a UIBackgroundTaskIdentifier, save data to a Core Data db and finally push the data to a server (I’m using Parse), after a […]

Weird Switch error in Obj-C

I have this switch statement in my code: switch(buttonIndex){ case 0: [actionSheet dismissWithClickedButtonIndex:buttonIndex animated:YES]; break; case 1: UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init]; imagePicker.delegate = self; imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera; [self presentModalViewController:[imagePicker autorelease] animated:YES]; break; default: [self openEmailViewInViewController:self]; } And at the UIImagePickerController instantiation in Case 1 I am getting an error: error:expected expression before ‘UIImagePickerController’ […]

How can you read a files MIME-type in objective-c

I am interested in detecting the MIME-type for a file in the documents directory of my iPhone application. A search through the docs did not provide any answers.

Is it possible to show an Image in UIAlertView?

Is it possible to add image in an UIAlertView, like showing an image from the plist file?

Valid use of accessors in init and dealloc methods?

I’ve heard now from several sources (, cocoa-dev, the documentation, blogs, etc) that it is “wrong” to use accessors and settings (foo, setFoo:) in your init and dealloc methods. I understand that there is there is a remote possibility of confusing other objects that are observing the property if you do so. (a simple example […]

Objective C: SHA1

How do i sha1 a string or set of numbers in Objective c?

NSArray Equivalent of Map

Given an NSArray of NSDictionary objects (containing similar objects and keys) is it possible to write perform a map to an array of specified key? For example, in Ruby it can be done with:

Finding the Current Active Window in Mac OS X using Python

Is there a way to find the application name of the current active window at a given time on Mac OS X using Python?

How Do I Blur a Scene in SpriteKit?

How would I add a gaussian blur to all nodes (there’s no fixed number of nodes) in an SKScene in SpriteKit? A label will be added on top of the scene later, this will be my pause menu. Almost anything would help! Something like this is what I’m going for:

How to convert a unichar value to an NSString in Objective-C?

I’ve got an international character stored in a unichar variable. This character does not come from a file or url. The variable itself only stores an unsigned short(0xce91) which is in UTF-8 format and translates to the greek capital letter ‘A’. I’m trying to put that character into an NSString variable but i fail miserably. […]