I want to save some user preferences, but
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
just returns nil.
iOS-Developper Library says, that this should return the existing shared defaults object or create one if none exists... What am I missing?
I also use Appirater and there all this stuff seems also not to work...
This code gets called when the user pushes a button...
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
int index = ([defaults integerForKey:#"BackgroundColorSpecifier"]+ 1)%self.backgroundColors.count;
[defaults setInteger:index forKey:#"BackgroundColorSpecifier"];
[defaults synchronize];
This gets called in application: didFinishLaunchingWithOptions:
NSUserDefaults *standardDefaults = [NSUserDefaults standardUserDefaults];
[standardDefaults registerDefaults:#{#"BackgroundColorSpecifier": #0}];
[standardDefaults synchronize];
When I debug this code snippets the green "position-indicator" jumps around in a very strange manner...
I don't have any clue, whats going on... Please help!
This is far more likely to be a problem with the debugger than anything else, particularly with your other issues. I've seen similar things in my own projects but don't have a reliable way of clearing it out other than the usual restart / clean options.
NSLogs will usually give more consistent results than the debugger if the debugger is having an off day.
NSUserDefaults isn't broken. We'd have heard about it by now.
you can use this function to log you userDefaults dic
- (void)logCache
{
NSDictionary * dic = [[NSBundle mainBundle] infoDictionary];
NSString *bundleId = [dic objectForKey: #"CFBundleIdentifier"];
NSUserDefaults *appUserDefaults = [[NSUserDefaults alloc] init];
NSDictionary *cacheDic = [appUserDefaults persistentDomainForName: bundleId];
NsLog(#"cacheDic::%#",cacheDic);
}
Related
I have exhausted all my resources. The very simple process of storing a boolean value in standardUserDefaults simply does not work for me. Here's my test code:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setBool:true forKey:#"BoolKey"];
[defaults setObject:#"Hello!!!" forKey:#"StrKey"];
[defaults synchronize];
BOOL b = [defaults boolForKey:#"BoolKey"]; // b equals NO
NSString *s = [defaults stringForKey:#"StrKey"]; // s equals "Hello!!!"
I can't understand why strings are stored fine, while booleans are not. Does anyone have any idea? I'm using XCode 6.0.1 (6A317).
Update: I found that changing the KeyName actually solved my problem. My boolean key was named LoginOK. I changed it to CredentialsStored, and now it loads correctly. Weird though...
I copy pasted your code and executed
Have look to bottom right in console
BOOL returned YES
This issue has nothing to do with Xcode 6.0.1 (6A137). Your code is correct. I believe there could be an error at when you are calling or executing these commands. You should try and debug, start with a simple example and NSlog the values. Click on your iOS Simulator >> Reset Contents and Settings and try.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setBool:true forKey:#"BoolKey"];
[defaults setObject:#"Hello!!!" forKey:#"StrKey"];
[defaults synchronize];
BOOL b = [defaults boolForKey:#"BoolKey"];
NSLog(#"%d",b);
NSString *s = [defaults stringForKey:#"StrKey"];
NSLog(#"%#",s);
I have two completely separate tasks being carried out but somehow they seem to connect.
In ViewController 1, I have:
NSString *foo = #"foo";
NSUserDefaults *default1 = [NSUserDefaults standardUserDefaults]
[default1 setObject:foo forKey:#"foo"];
[default1 synchronize];
and when I do:
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"foo"]);
The value printed is what I expect it to be.
In ViewController 2, I have:
NSString *bar = #"bar";
NSUserDefaults *default2 = [NSUserDefaults standardUserDefaults]
[default2 setObject:bar forKey:#"bar"];
[default2 synchronize];
And same again when I NSLog it, the value is what I expect it to be.
But somehow when i try to print object #"foo" again it gives me the value for the second object, in this case #"bar"
Any guidance on why my original value is being overridden by the second value even tough the variable/key names are different in the 2 classes?
You are doing this for both:
[foo setObject:bar forKey:#"bar"];
Shouldn't it be:
[defaults1 setObject:foo forKey:#"foo"];
And
[defaults2 setObject:bar forKey:#"bar"];
There is however, a greater problem:
NSString *foo = #"foo";
NSUserDefaults *default1 = [NSUserDefaults standardUserDefaults];
[default1 setObject:foo forKey:#"foo"];
[default1 synchronize];
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"foo"]);
NSString *bar = #"bar";
NSUserDefaults *default2 = [NSUserDefaults standardUserDefaults];
[default2 setObject:bar forKey:#"bar"];
[default2 synchronize];
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"bar"]);
Will work properly, however you're creating defaults1 and defaults2 which are both instances of standard defaults, so:
NSUserDefaults * defaults1 = [NSUserDefaults standardUserDefaults];
NSUserDefaults * defaults2 = [NSUserDefaults standardUserDefaults];
[NSUserDefaults standardUserDefaults];
Are all pointers to the standardUserDefaults singleton. So they are identical instances. You could simply do:
NSUserDefaults *standardDefaults = [NSUserDefaults standardUserDefaults];
NSString *foo = #"foo";
[standardDefaults setObject:foo forKey:#"foo"];
NSString *bar = #"bar";
[standardDefaults setObject:bar forKey:#"bar"];
[standardDefaults synchronize];
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"foo"]);
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"bar"]);
You can print out the entire set of user defaults with code like this
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *dictionary = [defaults dictionaryRepresentation];
NSLog( #"%#", dictionary );
Note that Apple puts lots of garbage in the user defaults, so you'll have to scroll to the end to see foo and bar. I'm guessing that you have a typo in code that you haven't shown us, and either foo is being overwritten, or foo simply isn't being displayed properly.
The current code in your question (after 1 edit) is all good and should work correctly.
How to know whether NSUserDefaults contains any value?How to check whether its empty?
There isn't a way to check whether an object within NSUserDefaults is empty or not.
However, you can check whether a value for particular key is nil or not.
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSObject * object = [prefs objectForKey:#"your_particular_key"];
if(object != nil){
//object is there
}
NSUserDefaults *data = [NSUserDefaults standardUserDefaults];
NSString *string = [data objectForKey:#"yourKey"];
if(string==nil)
NSlog(#"nil")
Take a look at NSUserDefault documentation
// For saving the values
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
// saving an NSString
[userDefaults setObject:#"Ttest" forKey:#"key"];
// --- For Retrieving
NSUserDefaults * userDefaults = [NSUserDefaults standardUserDefaults];
// getting an NSString
NSString *myString = [userDefaults stringForKey:#"key"];
To check whether a specific value is set or not, no matter of its location (global or application's), check the returned value of -[NSUserDefaults objectForKey:]
id obj = [[NSUserDefaults standardUserDefaults] objectForKey:#"My-Key-Name"];
if (obj != nil) {...}
To check if the application (bundle) has any settings stored in user defaults:
NSUserDefaults* sdu = [NSUserDefaults standardUserDefaults];
NSString* bundleId = [[NSBundle mainBundle] bundleIdentifier];
NSDictionary* mainBundleSettings = [sdu persistentDomainForName:bundleId];
NSLog(#"%#", mainBundleSettings);
If you are interested in all possible values for which -[NSUserDefaults objectForKey:] will return something, including system global settings, simply call
NSDictionary* allPossibleSettings = [sdu dictionaryRepresentation];
NSUserDefaults is never empty. It combines global settings, bundle's settings, temporary data and maybe something else. For example, if you call:
[[NSUserDefaults standardUserDefaults] objectForKey:#"NSBoldSystemFont"]
you will get the #"LucidaGrande-Bold" string value which will be taken from global settings, even when your application has never set this value.
I want to set some initial values for my NSUserDefault keys so that the first run of the app has some reasonable initial settings. I thought I ran across a simple way to do this in the app bundle .plist, but now I can't find it. Any ideas?
You should use the registerDefaults method of NSUserDefaults. Prepare a plist file in your bundle that contains the default preferences and then use that plist to register the defaults.
NSString *defaultPrefsFile = [[NSBundle mainBundle] pathForResource:#"defaultPrefs" ofType:#"plist"];
NSDictionary *defaultPreferences = [NSDictionary dictionaryWithContentsOfFile:defaultPrefsFile];
[[NSUserDefaults standardUserDefaults] registerDefaults:defaultPreferences];
You have to execute this code on every launch of your app. It will add these values to a separate domain in the user defaults hierarchy. Whenever your app's user defaults don't provide a value for a certain key, NSUserDefaults will fall back to this domain and retrieve the value from there.
If you have many default values, let use ola's answer, otherwise this is good for a few params
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if (![defaults boolForKey:USERDEFAULT_IS_INITIALIZED]) {
[defaults setBool:YES forKey:USERDEFAULT_IS_INITIALIZED];
// Set initial values
...
[defaults synchronize];
}
if ([[[[NSUserDefaults standardUserDefaults] dictionaryRepresentation] allKeys] containsObject:#"initialValuesHaveBeenWritten"])
{
[[NSUserDefaults standardUserDefaults] setValue:obj1 forKey:key1];
[[NSUserDefaults standardUserDefaults] setValue:obj2 forKey:key2];
[[NSUserDefaults standardUserDefaults] setValue:obj1 forKey:#"initialValuesHaveBeenWritten"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
NB: Not tested, done from memory
-(void) loadDef
{
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
_removeAd=[userDefaults boolForKey:SAVE_AD_STATUS];
NSString* strDefSetting=[userDefaults stringForKey:SAVE_STATUS_ADSETTING];
if(strDefSetting==nil
||[strDefSetting isEqualToString:#""]
)
{
strDefSetting=#"0.5";
}
_floatAdmob=strDefSetting.floatValue;//0.5;
}
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
How can I save and load the alpha values of a UIButton in an app?
I would like to save the state of the UIButton (e.g. its alpha value and whether it is hidden or not) and this would then load up when the user quits and reloads the app.
I've tried some bits of code with NSUserDefaults but with no luck.
Could somebody help with some sample code so that I can save and load the button's state?
Thanks,
James
Related to Shaharyar's answer (i don't know how to comment):
in this case you need to use NSNumber.
[[NSUserDefaults standardUserDefaults] setValue:[NSNumber numberWithFloat:SOME_FLOAT] forKey:KEY];
because float is not an object, but NSNumber is one.
EDITED:
1) To make sure your defaults are created after the application runs at first time:
in your AppDelegate's initialize-method:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *appDefaults = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithFloat:SOME_FLOAT], #"YOUR_KEY",
nil];
[defaults registerDefaults:appDefaults];
2) Updating defaults after:
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setFloat:FLOAT_VALUE forKey:#"YOUR_KEY"];
[prefs synchronize];
3) Read defaults:
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
float FLOAT_VALUE = [prefs floatForKey:#"YOUR_KEY"];
Can you post some of the code?
NSUserDefaults is the place to store such information..
Assumption:
Did you make a call to [NSUserDefaults synchronize] after setting the values?
Code:
// Setting a value
[[NSUserDefaults standardUserDefaults] setValue:VALUE forKey:KEY];
[[NSUserDefaults standardUserDefaults] synchronize];
// Getting a value
NSString *var1 = [[NSUserDefaults standardUserDefaults] valueForKey:KEY];
In your case it would be:
// Setting a value
[[NSUserDefaults standardUserDefaults] setFloat:VALUE forKey:KEY];
[[NSUserDefaults standardUserDefaults] synchronize];