FAQ Database Discussion Community


Can't make my activity appear in the toolbar (WWF)

workflow,foundation
I'm using Windows Workflow Fundation and I can not make my new activity appear in the toolbox in order to use it in my workflow.

NSTimer stops when view controller is not the selected tab or not showing

ios,swift,cocoa-touch,nstimer,foundation
I have a strange problem with my countdown timer. It fires off normally when my start button is hit, and is reinstantiated correctly when I close the app and relaunch it again. However, when I select a different tab and stay there for a while, it stops counting down, then...

Swift 2 : NSData(contentsOfURL:url) returning nil

ios,json,xcode,foundation,swift2
I have a webpage address which contains a JSON file. I'm trying to access the JSON file as NSDictionary in Swift 2. Every time I call NSData(contentsOfURL:url!) where url is type of NSURL?, it returns nil. I'm using Xcode 7 Beta, and the project was first made in Xcode 6....

Array has error after being retrieved from NSUserDefaults

arrays,cocoa-touch,swift,nsuserdefaults,foundation
I have a custom class for which I've implemented the NSCoder protocol. My intended data model is to store an array of these custom classes in NSUserDefaults. I encode it as NSData and store it in an array, which I store in NSUserDefaults. However when I retrieve the stored data...

Why is it okay to write acos(1.0) but not okay to write acos(1)?

swift,foundation
In Swift, if you have two variables : var a:Int = 2 var b:Double = 3.4 And if you try to do : var c = a+b It will trigger an compile-time error, because you cannot add two variables that aren't of the same type. But still, you could do...

Format to MM:SS using NSDateComponentsFormatter

ios,osx,cocoa-touch,foundation,nsdatecomponentsformatter
I'm trying to format to MM:SS using NSDateComponentsFormatter: let formatter = NSDateComponentsFormatter() formatter.zeroFormattingBehavior = .Pad formatter.allowedUnits = .CalendarUnitMinute | .CalendarUnitSecond let time: NSTimeInterval = 5 let timeText = formatter.stringFromTimeInterval(time) The problem is, that even though I specified .Pad, the result is 0:05 instead of 00:05. Here's a relevant piece from...

NSFileManager does not properly work

objective-c,foundation
I want to move 2 files with NSFileManager, but it isn't moving my files: at myfolder There are 5 text file, that i will remove all this files My code: BOOL isDir; if([[NSFileManager defaultManager] fileExistsAtPath:@"/volume/netrt/myfolder/" isDirectory:&isDir]) { [[NSFileManager defaultManager] removeItemAtPath:@"/volume/netrt/myfolder/*" error:nil]; // for delete all files [[NSFileManager defaultManager] movItemAtPath:@"/rdns/macross/text1.txt" toPath:@"/volume/netrt/myfolder/"...

What's the most efficient way to store time zone info in Realm?

ios,osx,nsdate,realm,foundation
I have a Realm object that contains an NSDate timestamp, representing the time at which a user recorded something. I need to add time zone info to this, so that I know what the local time zone was when the user created the object (in order to do accurate date...

How can I get screenshot from all displays on MAC?

osx,screenshot,quartz-graphics,foundation,cgimage
I try to get the screenshot from all monitors connected with my MAC to one picture. I know, how I can do this if every monitor's screenshot will saved to different pictures, but it is not what I want. I found function CGGetDisplaysWithRect, but my solution don't work, because output...

How to observe notifications from a different application?

objective-c,osx,cocoa,foundation,airserver
I'd like to get notified when a certain application triggers an event. I'm not an Objective-C developer nor do I know the OS X APIs—so I hope this question is not too basic. My goal is to write the meta info of the currently playing song to a log file....

How to extend the Swift Dictionary type to return a non-empty String or nil

ios,swift,cocoa,cocoa-touch,foundation
I'm writing an extension to Dictionary so that when I give it a String key, it'll return me a String only if the value associated with the key is non-nil and not empty. extension Dictionary { subscript(key: String) -> String? { if let string = super.subscript(key) { if string.isEmpty ==...