I have a question about NSUserDefault. Currently, i wanna write a function which save the favorite school into a list.
I have school name and school Id. So each time I save, school name + school id will be 1 dictionary object.
Then I save into NSUserDefault base on the id as key. I want to know the number of objects I saved into NSUserDefault. Or How can I get all of the objects out of NSUserDEfault since each of my key is different. Please help me out. below is my code:
NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *schools = [[NSMutableDictionary alloc] init];
[schools setObject:schoolName forKey:kSchoolName];
[schools setObject:schoolID forKey:kSchoolID];
[userDefault setObject:schools forKey:schoolID];
How many objects are you storing? Maybe this isn't the best use for NSUserDefaults.
But to directly answer your question:
NSUInteger count =
[[[NSUserDefaults standardUserDefaults] dictionaryRepresentation] count];
You would want to use a same key to store your schools dictionary.I mean,
[userDefault setObject:schools forKey:#"Schools List"];
Then to retrieve it
NSDictionary *schools = [userDefault ObjectforKey:#"Schools List"];
[[schools allkeys]count];
That will give you the count.
Related
In my application, I am using a login form to enter into the application, also using NSUserDefaults to store user preferences, for example:
[storeData setObject:self.loginField.text forKey:#"USEREMAIL"];
[storeData setObject:self.PasswordField.text forKey:#"PASSWORD"];
Like I stored, if a new user logs in the NSUserDefaults stored value will be changed. But I want both preferences (ex:new userid and old userid as well as password). So please explain how to store multiple values for same key?
One way to solve this would be to store a NSDictionary with UserIDs as keys and the passwords as values.
Another option is to use Keychain as it specifically designed for this kind of thing and is also more secure.
Create a Global NSMutableArray and add above details in NSDictionary Objects and Store all Objects in array.This way you will have all user objects.You can get it whenever you want.
first of all create global array with AppDelegate class, for example..
userDefaults = [NSUserDefaults standardUserDefaults];
NSData *dataRepresentingtblArrayForSearch = [userDefaults objectForKey:#"arrScheduleDates"];
if (dataRepresentingtblArrayForSearch != nil) {
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingtblArrayForSearch];
if (oldSavedArray != nil)
arrScheduleDates = [[NSMutableArray alloc] initWithArray:oldSavedArray];
else
arrScheduleDates = [[NSMutableArray alloc] init];
} else {
arrScheduleDates = [[NSMutableArray alloc] init];
}
[arrScheduleDates retain];
after that when you want to store the new record then get all record from arrScheduleDates array and after that add the new record and after that store like whole array like above..
i hope you understand and its helpful for you...
:)
The absolute easiest way to meet your requirements is to use the user's email address (assuming they're all unique) as the storage key for your dictionary, and the password as the value.
If you need to store more than the password, then the value of the key would be another dictionary with keys and values for the user.
An example of the simple case would look similar to :
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSDictionary *storedUsers = [userDefaults objectForKey:#"userData"];
if (nil == storedUsers) storedUsers = [NSDictionary dictionary];
NSMutableDictionary *mutableStoredUsers = [NSMutableDictionary dictionaryWithDictionary:storedUsers];
NSString *userPassword = [self.PasswordField.text copy]; //add autorelease if you aren't using ARC
NSString *userEmail = [self.loginField.text copy]; //add autorelease if you aren't using ARC
if (nil != userEmail)
{
[mutableStoredUsers setObject:userPassword forKey:userEmail];
}
[userDefaults setObject:[NSDictionary dictionaryWithDictionary:mutableStoredUsers] forKey:#"userData"];
[userDefaults synchronize];
first download and import files of given link
https://github.com/ldandersen/scifihifi-iphone/tree/master/security
then where u want to store user preferences write this code
[SFHFKeychainUtils storeUsername:loginField.text andPassword:PasswordField.text forServiceName:#"dhaya" updateExisting:YES error:&error];
where u want password write this code
NSString *password = [SFHFKeychainUtils getPasswordForUsername:loginField.text andServiceName:#"dhaya" error:&error];
NSLog(#"passwordpassword %#",password);
this will working great....
I am new to iOS development and could not find a way to solve this problem:
I have an app that has two views: one where the user enters some information (say a string), and another view where there is a tableview that includes all the strings that were ever entered (like a history view).
What I am trying to find is a good way to store the input string, then load it into the table view data source once the user switches to the history. I tried to use NSUserdefault but with not much success. Just getting messed up with the data structures, etc.
Here is what I am doing on the main view (where the user enters the input string):
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *arr1 = [[NSMutableArray alloc] init];
arr1 = [defaults arrayForKey:#"historyNames"];
[arr1 addObject:string];
[defaults setObject:arr1 forKey:#"historyNames"];
From some reason I get a warning where I read to arr1, and honestly, I doubt that should work anyway.
Can anyone suggest how I could modify this to work properly and achieve what I am looking for?
Thanks.
[defaults arrayForKey:#"historyNames"];
Will return nil if you never initialized and saved an array for that key in NSUSerDefaults.
If you initialize and array and set it once (look up how to initialize default values for NSUserDefaults), it will return a proper array.
Then you can just do
NSMutableArray *arr1 = [NSMutableArray arrayWithArray:[[defaults arrayForKey#"historyNames"]];
Depending on how many elements this array will have, you may be better off using Core Data. Using user defaults is not very efficient for many/large values, just for small settings and things like that.
When your application starts up, look in user defaults to see if you have an array object already from the last time you used it. If there isn't one, call alloc and init for arr1. (You don't want to call it if you're accessing it from defaults.)
NSMutableArray * arr1;
arr1 = (NSMutableArray *) [defaults objectForKey:#"historyNames"];
if (!arr1) {
arr1 = [[NSMutableArray alloc] initWithCapacity:20];
}
In your main view, just add the input string, and save the defaults.
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setObject: arr1 forKey: #"historyNames"];
[prefs synchronize];
i need your help,i Am stuck in a simple problem,i done a lot of googling but did not get solution.
I want to store Top 5 scores and with names, i done score by NSUserDefaults but don't know how to store it with names.Please help me.I really need your help.
THANKS...
you can save into user defaults as
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
NSDictionary* dict = [[NSDictionary alloc] initWithObjectsAndKeys:#"jonny",#"name",#"100",#"score", nil];
NSArray* arr = [[NSArray alloc] initWithObjects:dict, nil];
[defaults setObject:arr forKey:#"list"];
[defaults synchronize];
[dict release];
[arr release];
and read the values as
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
NSArray* arr = [defaults objectForKey:#"list"];
NSLog(#"%#",[arr objectAtIndex:0]);
this works fine for you, it will be a array of dictionaries.
I recommend you familiarize yourself with basic Objective-C collection classes. You can use an NSDictionary to store objects, and those objects can be other objects. You can use this dictionary in combination with NSUserDefaults to store only what you want to store, after having some logic in your app that analyzes your collection class.
Pick up a good book on Objective-C and study sets, arrays and dictionaries.
I need to pre-populate and save an array in NSUserDefaults so that downstream methods can read and write to ten values stored there. I've constructed this workable solution, but is there a better way of doing this?
Any insight is appreciated!
lq
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *myArray = [[NSMutableArray alloc] init];
// Set the array with ten Zero Value placeholders
for (NSUInteger i = 0; i < 10; ++i) {
[myArray addObject:[NSNumber numberWithInt:0]];
}
[userDefaults setObject:myArray forKey:#"someKeyName"];
[myArray release];
Later methods call this array like this:
- (void)doSomethingUseful {
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *someUsefulArray = [[NSMutableArray alloc] initWithArray:[userDefaults objectForKey:#"someKeyName"]];
// read some values, write some values: int someInt = [someUsefulArray objectAtIndex:3]; // etc.
// store array values back to NSUserDefaults . . .
// IS THERE A WAY TO READ AND WRITE DIRECTLY TO INDEX 3 of the NSUserDefaults array instead???
[someUsefulArray release]
}
I've actually done the same thing in a shipping application. Sure, it doesn't feel elegant, but it does the job.
The only more elegant, and more convoluted, solution would be to use a data-driven approach:
Have a .plist file containing what you consider to be your default settings.
If the program detects that the user defaults is empty, it will load this default plist, and commit it to NSUserDefaults.
Using this method your code is not responsible for building the objects. However, if you are trying to accomplish a schema-upgrade, you're going to need to go back to the code.
I'm writing an application which uses NSUserDefaults as the data storage mechanism, and am hitting a problem when trying to save data (that conforms to the Property List protocols):
+ (BOOL)storeAlbum:(Album *)album
{
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *albums = (NSMutableDictionary *)[prefs objectForKey:#"my_adventure_book_albums"];
NSLog(#"Existing albums: %#",albums);
if (!albums)
albums = [NSMutableDictionary dictionaryWithObject:album forKey:#"album"];
else
[albums setObject:album forKey:#"album"];
NSLog(#"%#",album);
[prefs setObject:albums forKey:#"my_adventure_book_albums"];
return [prefs synchronize];
}
I get this output:
2010-06-29 17:17:09.929 MyAdventureBook[39892:207] Existing albums: (null)
2010-06-29 17:17:09.930 MyAdventureBook[39892:207] test
2010-06-29 17:17:09.931 MyAdventureBook[39892:207] *** -[NSUserDefaults setObject:forKey:]: Attempt to insert non-property value '{
album = test;
}' of class 'NSCFDictionary'.
The description method of Album looks like:
- (NSString *)description
{
// Convert to a NSDictionary for serializing
if (!title) title = #"";
if (!date) date = [NSDate dateWithTimeIntervalSinceNow:0];
if (!coverImage) coverImage = #"";
if (!images) images = [[NSArray alloc] initWithObjects:#"",nil];
//NSDictionary *dict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:title,date,coverImage,images,nil] forKeys:[NSArray arrayWithObjects:#"title",#"date",#"coverImage",#"images",nil]];
//NSDictionary *dict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:title,nil] forKeys:[NSArray arrayWithObjects:#"title",nil]];
//return [dict description];
return #"test";
}
All of the commented-out lines have the same result, so I just decided to see if the NSString "test" would work, which it (of course) doesn't.
But the object you put inside the dictionary, an Album* is most likely not a property list object, is it? Every object, all the way down, needs to be a property list object for this to work. A description method isn't good enough to make this happen.
As a workaround, you can use NSCoding and an NSKeyedArchiver to write out your dictionary to an NSData, which you can store among the preferences.
You can only put basic foundation types into a property list. NSUserDefaults writes preferences out as a property list. See here for property list allowed types. In a nutshell, it is numbers, strings, data, dates, and arrays and dictionaries of those. Dictionaries must have string keys.
NSUserDefaults always returns immutable objects, so you can't just cast them to mutable. Do [prefs objectForKey:#"my_adventure_book_albums"] mutableCopy] (and remember to release it when finished).