This code gives me always NO in my application. It does indeed work in any other project I copy it... so something must be messed up with my standardUserDefaults, but I absolutely don't know how this can happen and how to solve it!
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setBool:YES forKey:@"myKey"];
BOOL test = [defaults boolForKey:@"myKey"];
// test is ALWAYS NO here!
Can anybody hint me, where to start or how to get rid of this?
It's a mixed project with swift and objective c and get the same behavior in me AppDelegate.swift, when I put this directly in my applicationDidFinishLaunching
let defaults = NSUserDefaults.standardUserDefaults()
defaults.setBool(true, forKey: "myKey")
let test = defaults.boolForKey("myKey")
// test ALWAYS false here
Before someone asks: - yes, even with synchronize called between it - yes this is the whole code, nothing between the lines... set and get it right after does not work
I found a solution, how to fix it, but not why this happens and no clean, good way so far.
If anybody could explain this and give me a better solution, do so!
the problem was: If you delete the container of a sandboxed app, you also delete the plist for the NSUserDefaults and it's not created again and so NSUserDefaults simply is not working.
the workaround: As I found here https://ind.ie/labs/blog/app-sandbox-updating-nsuserdefaults-fails-after-deleting-apps-container-directory/ it's a problem with the permanent bookmark of the system. Well just to empty the trash does not work for me, but what worked: I simply created the missing file!
touch ~/Library/Containers/com.example.myapp/Data/Library/Preferences/com.example.myapp.plist
来源：https://stackoverflow.com/questions/28881622/osx-nsuserdefaults-not-working