Check if my IOS application is updated

Question

I need to check when my app launches if it was being updated, because i need to make a view that only appears when the app is firstly installed to appear again after being updated.

Answer 1

You could save a value (e.g. the current app version number) to NSUserDefaults and check it every time the user starts the app.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {     // ...      NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];      NSString *currentAppVersion = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];     NSString *previousVersion = [defaults objectForKey:@"appVersion"];     if (!previousVersion) {         // first launch          // ...          [defaults setObject:currentAppVersion forKey:@"appVersion"];         [defaults synchronize];     } else if ([previousVersion isEqualToString:currentAppVersion]) {         // same version     } else {         // other version          // ...          [defaults setObject:currentAppVersion forKey:@"appVersion"];         [defaults synchronize];     }        return YES; } 

The swift-2 version looks like this:

let defaults = NSUserDefaults.standardUserDefaults()  let currentAppVersion = NSBundle.mainBundle().objectForInfoDictionaryKey("CFBundleShortVersionString") as! String let previousVersion = defaults.stringForKey("appVersion") if previousVersion == nil {     // first launch     defaults.setObject(currentAppVersion, forKey: "appVersion")     defaults.synchronize() } else if previousVersion == currentAppVersion {     // same version } else {     // other version     defaults.setObject(currentAppVersion, forKey: "appVersion")     defaults.synchronize() } 

The swift-3 version looks like this:

let defaults = UserDefaults.standard  let currentAppVersion = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! String let previousVersion = defaults.string(forKey: "appVersion") if previousVersion == nil {     // first launch     defaults.set(currentAppVersion, forKey: "appVersion")     defaults.synchronize() } else if previousVersion == currentAppVersion {     // same version } else {     // other version     defaults.set(currentAppVersion, forKey: "appVersion")     defaults.synchronize() }