nsuserdefaults

问题 I would like to update an app to add a tour on first launch. I would ordinarily handle this with some kind of NSUserDefaults key. However, there are pre-existing existing versions of the app already released. How can I trigger some behavior on first launch of the app, but only for fresh installs and not for the first launch after an update? 回答1: you can check app version via web service. and warn users to update the app. And this case, internet connection required. 回答2: On launch, check for

问题 When I say not running in the background, I mean when the user double clicked their home button and swipes up, the button will reenable This is the code in my viewDidLoad if let waitingDate:Date = UserDefaults.standard.value(forKey: "waitingDate") as? Date { let currentDate = Date() if(currentDate.compare(waitingDate) == ComparisonResult.orderedDescending) { getPointsOutlet.isEnabled = true } } This is the code in the @IBAction func getPointsOutlet.isEnabled = false let newDate = Calendar

问题 Hello i have implemented Share extension for my app in which picks images from gallery and send to a particular view. Now the problem is when i'm trying to save array of images(images picked from gallery) func manageImages() { let content = extensionContext!.inputItems[0] as! NSExtensionItem let contentType = kUTTypeImage as String for (index, attachment) in (content.attachments as! [NSItemProvider]).enumerated() { if attachment.hasItemConformingToTypeIdentifier(contentType) { attachment

问题 I have UIDatepicker .I have few queries to ask 1.)When i tap on UIButton the dates in datepicker gets retuns to minimum value since i have given maximum and minimum value . In doing that function the date in datepicker appears to be in non highlighted manner ![enter image description here. The link mentioned below shows how the date appears in datepicker http://postimg.org/image/7mlxiq6sz/ - (IBAction)notificationButtonChanged:(UIButton *)control { NSUserDefaults *defaults = [NSUserDefaults

问题 In this code I have a selected state and deselected state for my button. When the button has been pressed, it changes to green and when pressed again it changes to red to represent a deselected state. However, all this is in a DetailViewController and when I select a particular row from my tableView then click the button to show green and go back and try a different row, the button shows green on this other row which signifies that I've pressed it(I haven't). I was wondering if there was a

问题 I read the question Easy way to see saved NSUserDefaults? I found the .plist file for the app, but where's the one for the testing bundle? 回答1: If you use Xcode 4's integration with OCUnit, it injects the test bundle into a running application. NSUserDefaults are therefore saved in the application itself. This is problematic for unit tests: When you run the app manually, your defaults may have been overwritten by your tests. Instead of using [NSUserDefaults standardUserDefaults] directly, use

问题 I am encountering a strange issue in iOS 8.2 where [NSUserDefaults standardUserDefaults] is returning nil on iPhone. This same logic untouched has worked on all previous releases of iOS. I have a universal app which has two different settings.plist one for iPad and the other for iPhone list as follows; Settings.bundle- -Root.plist -Root~iphone.plist When installed on devices the correct settings pane displays and the user can input the appropriate values for the given fields. Though in my app

问题 I use NSUserDefaults to save a switch on/off and so far it is good. It remembers the switch position in next session. Now to the thing which I do not understand. I use the same switch (with the same name)in another view, let´s say a flip view which is pushed in from the first view. If I change the switch in the first view it is automatically changed in the flip view. But the other way round, if I change it in the flip view it is not changed in the first view when I go back. Only if I restart

问题 I'm trying to save this date in NSUSerDefaults: 2011-04-14T13:18:25+0000 But I don't want the last bit (+0000), so I chopped it off using this method: NSString *since = [last objectForKey:@"updated_time"]; NSString *cutOff = @"+0000"; NSRange range = [since rangeOfString:cutOff]; self.lastUpdated = [since substringToIndex:range.location]; [[NSUserDefaults standardUserDefaults] setObject:lastUpdated forKey:@"lastUpdated"]; As you can see, it's just a very simple operation that will chop the

问题 I am trying to save an array of optionals Strings to NSUserDefaults , but unfortunately it doesn't work: var textFieldEntries: [String?] ... func encodeWithCoder(aCoder: NSCoder!) { aCoder.encodeObject(textFieldEntries, forKey: "textFieldEntries") // prints error: Cannot convert value of type '[String?]' // to expected argument type 'AnyObject?' } 回答1: [String?] is a Swift type that cannot be represented as a Foundation type. Normally, Swift Array bridges to NSArray , but an NSArray cannot