I am saving image data (NSData) as an Array in NSUserDefault,while relaunching the app and try to remove the imagedata from the array stored in NSUserDefault,the data is not removing ..
Suppose you have store image data with key 'imagedata' something like below line of code
[[NSUserDefaults standardUserDefaults] setObject:imageData forKey :#"imageData"];
How to remove data stored for key imageData is as below line of code:
NSMutableArray *arr= [[NSUserDefaults standardUserDefaults] objectForKey:#"imageData"]]mutableCopy];// If array is not mutable then make it mutable then remove
[arr removeObjectAtIndex:index];
[[NSUserDefaults standardUserDefaults] setObject:arr forKey :#"imageData"];
After checking your code updating my answer
UPDATE
Try method removeObjectIdenticalTo of array.
//sample data
NSArray *photos = [NSArray arrayWithObjects:#"photo1.png",#"photo2.png",#"photo2.png", nil];
//To save the array of data
NSUserDefaults *userPreferences = [NSUserDefaults standardUserDefaults];
[userPreferences setObject:photos forKey:#"FbPhoto"];
[userPreferences synchronize];
//To remove
[userPreferences removeObjectForKey:#"FbPhoto"];
[userPreferences synchronize];
Related
I am trying to remove an object from a dictionary which is in userdefaults.
NSMutableDictionary *userDefaults = (NSMutableDictionary*)[[NSUserDefaults standardUserDefaults] dictionaryRepresentation];
[userDefaults removeObjectForKey:#"XYZ"];
The above code removes the whole dictionary.
XYZ is a NSMutuableDictionary. I want to remove an object with key "Password" from XYZ.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *dict = [[defaults objectForKey:#"XYZ"] mutableCopy];
[dict removeObjectForKey:#"Password"];
[defaults setObject:dict forKey:#"XYZ"];
This should do it:
// Access the dictionary you want to edit as a mutable copy
NSMutableDictionary *dict = [[[NSUserDefaults standardUserDefaults] objectForKey:#"dictKey"] mutableCopy];
// Remove the object for the key
[dict removeObjectForKey:#"keyToRemove"];
// Set the dictionary back in user defaults
[[NSUserDefaults standardUserDefaults] setObject:dict forKey:#"dictKey"];
// Save your changes:
// If you need
// In applicationDidEnterBackground: in iOS >= 7.0
// If you are using iOS < 7.0
[[NSUserDefaults standardUserDefaults] synchronize];
I am try to add a NSMutableArray into the NSUserDefault but it is always retuning null.
I know that .so I'm even creating a mutable copy os array as well but still.
Values returned from NSUserDefaults
are immutable, even if you set a
mutable object as the value. For
example, if you set a mutable string
as the value for "MyStringDefault",
the string you later retrieve using
stringForKey: will be immutable.
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSMutableArray *myStoredEvents=[prefs objectForKey:#"MySavedEvents"];
NSMutableArray *myStoredEventsNew=[[NSMutableArray alloc]init];
myStoredEventsNew=myStoredEvents;
NSMutableArray *tempDic=[myevents objectAtIndex:eventId];//myevents a NSMutableArray
if(myStoredEventsNew != nil)
{
[myStoredEventsNew insertObject:tempDic atIndex:0];
}
else
{
[myStoredEventsNew insertObject:tempDic atIndex:myStoredEvents.count];
}
NSLog(#"New dictonary before modification :%#",tempDic);
[prefs setObject:myStoredEventsNew forKey:#"MySavedEvents"];
[prefs synchronize];
Try this code --
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSLog(#"DEBUG :: %#",[prefs objectForKey:#"MySavedEvents"]);
NSMutableArray *myStoredEvents;
if ([prefs objectForKey:#"MySavedEvents"] == NULL) {
myStoredEvents = [[NSMutableArray alloc]init];
}else{
myStoredEvents=[[prefs objectForKey:#"MySavedEvents"] mutableCopy];
}
NSMutableArray *tempDic=[myevents objectAtIndex:eventId];//myevents a NSMutableArray
[myStoredEvents addObject:tempDic];
NSLog(#"New dictonary before modification :%#",myStoredEvents);
[prefs setObject:myStoredEvents forKey:#"MySavedEvents"];
[prefs synchronize];
May this solve your problem
you can save array in NSuserdefaults like this :-
[[NSUserDefaults standardUserDefaults] setObject:yourArray forKey:#"MySavedEvents"];
[[NSUserDefaults standardUserDefaults] synchronize];
and you can put check condition to check NSuserdefault like this :-
NSObject * object = [prefs objectForKey:#"MySavedEvents"];
if(object != nil){
//object is there
}
You can put further conditions according to your need, this is just a basic structure of how to achieve this.
I am finding some problem while saving and retrieving data using nsuserdefaults.
What i want to do- iam accepting name and number from user from viewcontroller and saving it using nsuserdefault. when i click on save button i want to retrieve all the values from nsuserdefault and display it on tableview. now when i save the new data i want this data to get added to the existing data of nsuserdefault. can anyone help me with saving and retrieving nsuserdefault data.
----------MyCode---------------
nsuserdefaults *objdefault =[nsuserdefaults standarduserdefaults];
nameArray = [objdefault objectforkey:#"Name"];
[newNameArray addobject:txtName.text];
[nameArray addobject:newNameArray];
[objdefault setobject:nameArray forkey:#"Name"];
[objdefault synchronize];
all this saves and accepts null value
Please help. and thank you in advance
Use these methods to add name to NSUserDefaultsand get from NSUserDefaults
To add the name to NSUserDefaults call [self addNameToUserDefaults:#"abc"];
-(void)addNameToUserDefaults:(NSString *)name number:(NSString*)number{
NSUserDefaults *objdefault =[NSUserDefaults standardUserDefaults];
NSMutableArray *nameArray = [[objdefault objectForKey:#"NameAndNumber"] mutableCopy];
if(!nameArray)
nameArray = [#[] mutableCopy];
[nameArray addObject:#{#"name":name,#"number":number}];
[objdefault setObject:nameArray forKey:#"NameAndNumber"];
[objdefault synchronize];
}
To get all names from NSUserDefaults call NSMutableArray *names = [self getAllNames];
-(NSMutableArray *)getAllNames{
NSUserDefaults *objdefault =[NSUserDefaults standardUserDefaults];
return [[objdefault objectForKey:#"NameAndNumber"] mutableCopy];
}
It's not possible to add values for same in NSUSerDefaults. it will show you last value only. You should go for Core data or Sqlite. Still if you are not comfortable with that you can use plist to achieve this functionality.
This is what I have done in my project. You have to use NSMutableDictionary to add more value
- (void)addUserLocation:(NSString *)username location:(NSMutableDictionary *)location
{
NSString *currentUserKey = [NSString stringWithFormat:#"%#_%#", UserDefaultsKeyLocationData, username, nil];
NSMutableArray *oldData = [[NSMutableArray alloc]init];
if ([self loadUserLocation:username] != nil) {
oldData = [self loadUserLocation:username];
}
if (![oldData containsObject:location]) {
[oldData addObject:location];
}
[[NSUserDefaults standardUserDefaults] setObject:oldData forKey:currentUserKey];
[[NSUserDefaults standardUserDefaults] synchronize];
}
- (NSMutableDictionary *)loadUserLocation:(NSString *)username
{
NSString *currentUserKey = [NSString stringWithFormat:#"%#_%#", UserDefaultsKeyLocationData, username, nil];
return [[[NSUserDefaults standardUserDefaults] objectForKey:currentUserKey] mutableCopy];
}
If you want get all data. Please call loadUserLocation in your code
I normally save the selected indexPath of a UiTableView in NSUserDefaults, this is how I normally do it:
self.lastIndexPathUsed = indexPath.row;
NSUserDefaults *userdefaults = [NSUserDefaults standardUserDefaults];
[userdefaults setObject:[NSString stringWithFormat:#"%ld",(long)indexPath.row] forKey:#"lastIndexPathUsedForSellerType"];
[[NSUserDefaults standardUserDefaults] synchronize];
Then I restore it:
self.lastIndexPathUsed = [[[NSUserDefaults standardUserDefaults] objectForKey:#"lastIndexPathUsedForSellerType"] floatValue];
So self.lastIndexPathUsed is just a float value.
The above works fine on a single select table view. However on a multi-select tableview I can't see to get it working.
While the UITableView is on screen I save all the indexPaths into an array. However saving that array into NSUserDefaults causes a crash due to indexPath not being an object as such.
How to save an array how indexPaths into NSUserDefaults?
Try to archive your array to NSData before saving them to NSUserDefaults:
NSData *indexPathArrayData = [NSKeyedArchiver archivedDataWithRootObject:_indexPathArray];
and after getting the NSData from NSUserDefaults, you can unarchive them :
_indexPathArray = [NSKeyedUnarchiver unarchiveObjectWithData:indexPathArrayData];
You can try this :
[[NSUserDefaults standardUserDefaults] setObject:yourMutableArray forKey:#"Key"];
And then get it like this :
NSMutableArray *array = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:#"Key"]];
Hope it helps.
I'm trying to add elements to an NSMutableArray whenever a user selects a country. But each time I use [myarray setobject:#""];, it's adding the new value, overwriting my old value. I want this array as I'm using it in:
[[NSUserDefaults standardUserDefaults]setObject:(NSMutableArray *)selectedCountriesByUser forKey:#"userSelection"];
[[NSUserDefaults standardUserDefaults]synchronize];
I want an array which maintains the list of countries selected by the user even after the application is closed.
What should I do?
setObject replace all objects in array
for example, get value from NSUserDefault:
NSMutableArray *myMutableArray = [NSMutableArray arrayWithArray:[[NSUserDefault standardUserDefault] objectForKey:"userSelection"]];
you should use [myMutableArray addObject:"aCountry"]; without overwriting, but adding only
and after
[[NSUserDefaults standardUserDefaults]setObject:myMutableArray forKey:#"userSelection"];
[[NSUserDefaults standardUserDefaults]synchronize];
EDIT:
-(void) viewDidLoad {
//your selectedCountriesByUser
myMutableArray = [NSMutableArray arrayWithArray:[[NSUserDefault standardUserDefault] objectForKey:"userSelection"]];
}
...
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//add object to array
[myMutableArray adObject:"yourObj"];
[[NSUserDefaults standardUserDefaults]setObject:myMutableArray forKey:#"userSelection"];
[[NSUserDefaults standardUserDefaults]synchronize];
}
You're asking two different things. First, -setObject: is not a NS(Mutable)Array method. You are probably looking for the -addObject: method. So, to add an object to your NSMutableArray, you need to do:
[myMutableArray addObject:yourObject]
//Remember that `-addObject` is present only in NSMutableArray, not in NSArray
The second thing you are trying to achieve is to store the array in NSUserDefaults. to do so, after you add the object to the array you want, you should be fine do to so:
[[NSUserDefaults standardUserDefaults] setObject:myMutableArray forKey:#"userSelection"];
[[NSUserDefaults standardUserDefaults] synchronize];
// ARRAY DECLARATION AND ASSIGNMENT OF VALUES TO IT
NSMutableArray * selectedCountriesByUserArray=[[NSMutableArray alloc] init];
[selectedCountriesByUserArray addObject:#"value1"];
[selectedCountriesByUserArray addObject:#"value2"];
[selectedCountriesByUserArray addObject:#"value3"];
// STORING AN ARRAY WITH THE KEY "userSelection" USING NSUSERDEFAULTS
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:selectedCountriesByUserArray forKey:#"userSelection"];
[defaults synchronize];