I write a string in NSUserDefaults
[[NSUserDefaults standardUserDefaults] setObject: myString forKey: # "String"];
Then I take out this string from NSUserDefaults and return
- (NSString *) retrieveString
{
NSString * recoveredString = [[NSUserDefaults standardUserDefaults] objectForKey: # "String"];
return recoveredString;
}
Then in viewDidLoad write the returned string in another string
NSString * filePath = [self retrieveString];
I need to delete a string of NSUserDefaults after I was returning to her in - (NSString *) retrievestring
I do so
- (NSString *) retrieveString
{
NSString * recoveredString = [[NSUserDefaults standardUserDefaults] objectForKey: # "String"];
[[NSUserDefaults standardUserDefaults] removeObjectForKey: # "String"];
return recoveredString;
}
But this does not work, the line is not deleted.
How to fix it
Thanks to all.
NSUserDefaults updates its data periodically only, not each and every time a setter or getter is called. If you want an immediate update, call
[[NSUserDefaults standardUserDefaults] synchronize];
You need to add the synchronize call AND move your return call (so it is the last line in the method). So, your code should like this:
- (NSString *) retrieveString
{
NSString * recoveredString = [NSString stringWithString:[[NSUserDefaults standardUserDefaults] objectForKey: # "String"]];
[[NSUserDefaults standardUserDefaults] removeObjectForKey: # "String"];
[[NSUserDefaults standardUserDefaults] synchronize];
return recoveredString;
}
Related
While setting object to NSUserDefaults my App is crashing Randomly in iOS 12.Below is my code where the crash occurs
shared2 = [[NSUserDefaults alloc]initWithSuiteName:#"group.AppName"];
NSData *datashare = [NSKeyedArchiver archivedDataWithRootObject:_sharedData];
[shared2 setObject:datashare forKey:#"dicForToday"];
Not getting any crash logs as it happens randomly
Frequency of this crash is much more on iOS 12.
Normally you can use this method for save data
Post Method:
[[NSUserDefaults standardUserDefaults] setObject:object forKey:#"somename"];
Get Method:
NSMutableDictionary *dicCover = [[NSUserDefaults standardUserDefaults] valueForKey:#"somename"];
some time ,dictionary or array or not formatting right way we can use to achive your data like this to use NSUserdefault
Use Achive:
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:arrayUsers];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:#"somename"];
To get:
NSData *usersData = [[NSUserDefaults standardUserDefaults] valueForKey:#"somename"];
NSMutableArray *redirectionDic = [NSKeyedUnarchiver unarchiveObjectWithData:usersData];
NSUserDefaults *myDefaults = [[NSUserDefaults alloc]
initWithSuiteName:keyChainGroup];
[myDefaults setObject:userInfo forKey:key];
Try this
I'm creating a program that saves a String from one text field and an integer from a second text field. I am trying to use NSUserDefaults, but I can't seem to get either of them to save correctly when I run the program. It crashes when I press the save button with the breakpoint while handling the NSUserDefaults. Am I doing something wrong? I skimmed through the documentation, but it didn't help. Can I even use 2 different instances of NSUserDefaults?
- (IBAction)save:(id)sender {
//Save stuff fropm textfields
NSString* name = _nameText.text;
int count = [_countText.text intValue];
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
[[NSUserDefaults standardUserDefaults] setObject:name forKey:#"name"];
[[NSUserDefaults standardUserDefaults] setInteger:count forKey:#"count"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
- (IBAction)load:(id)sender {
//Load stuff from NSUserDefaults
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
NSString* loadstring = [defaults objectForKey:#"name"];
_nameText.text = loadstring;
NSUserDefaults* defaults2 = [NSUserDefaults standardUserDefaults];
NSInteger loadint = [defaults2 integerForKey:#"count"];
_countText.text = [NSString stringWithFormat:#"%li", (long)loadint];
}
Declare defaults = [NSUserDefaults standardDefaults]; in your viewDidLoad (and NSUserDefaults* defaults; in .h) and use this code:
- (IBAction)save:(id)sender {
//Save stuff fropm textfields
NSString* name = _nameText.text;
int count = [_countText.text intValue];
[defaults setObject:name forKey:#"name"];
[defaults setInteger:count forKey:#"count"];
[defaults synchronize];
}
- (IBAction)load:(id)sender {
//Load stuff from NSUserDefaults
_nameText.text = [defaults stringForKey:#"name"];
_countText.text = [NSString stringWithFormat:#"%li", (long)[defaults integerForKey:#"count"]];
}
I'm new to Objective-C and XCode and I've encountered such a problem.
How do you properly save the value to NSUserDefaults.
I have value in
[_textFields objectAtIndex:2]).text
And trying to do this
[[[NSUserDefaults standardUserDefaults] setValue:((UITextField *)[_textFields objectAtIndex:2]).text)) forKey:#"Phone"];
[[NSUserDefaults standardUserDefaults] synchronize];
How do you do it properly?
Use setObject:forKey: instead of setValue:forKey:
[[[NSUserDefaults standardUserDefaults] setObject:((UITextField *)[_textFields objectAtIndex:2]).text)) forKey:#"Phone"];
Update:
You code will work if you really have that text field in the array. Here is the step by step broken down code to make it more clear:
UITextField* textField = [_textFields objectAtIndex:2]; // get your text field
NSString* text = textField.text; // get the actual value we are going to store
[[[NSUserDefaults standardUserDefaults] setObject:text forKey:#"Phone"]; // store it
You are working with strings values. You should use setObjectForKey (save) and objectForKey (read). Here's an example
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSString *yourText = [[_textFields objectAtIndex:2] text]; // Your text
// Save
[userDefaults setObject:yourText forKey:kKey];
[userDefaults synchronize];
// Read
NSString *result = (NSString *) [userDefaults objectForKey:kKey];
Use method setObject:forKey: instead of setValue:forKey:
In NSUserDefaults class:
[[NSUserDefaults standardUserDefaults] setObject:"Your Object" forKey:#"Phone"];
You need to use the setObject:forKey: if you want to store property list objects (dictionaries, arrays, strings and numbers) in NSUserDefaults. See the docs.
i tried to use NSUserDefults to save and load a highscore(nsinteger) for my game.
i created an void function that check if the gameoverscore is bigger than my highscore and if it does to switch between them. i want that every time the game is over there will be a label which show my currect highscore.
to do this, i create a property for my NSUsweDefults, in my viewdidload i tried to load the currect highscore, and another function (checkIfHighscore).
here is my NSUserDefults property:
#property(readwrite) NSUserDefaults *prefs;
here is my viewdidload code:
NSInteger currectHighscore = [prefs integerForKey:#"highscore"];
highScoreLabel.text = [NSString stringWithFormat:#"%d",currectHighscore];
here is my checkIfHighscore:
-(void)checkIfHighScore
{
if(gameOverScore > highScore)
{
highScore = gameOverScore;
[self newHighscoreAnimation];
[prefs setInteger:highScore forKey:#"highscore"];
[prefs synchronize];
}
highScoreLabel.text = [NSString stringWithFormat:#"Highscore: %d", highScore];
}
when i enter to this viewcontroller my highscorelabel shows 0, like it doesnt save my highscore.
what do i do wrong?
thanks!
// Snippet used to save your highscore in the prefs.
int highScore = yourGameScore;
[[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:highScore] forKey:#"HighScore"];
[[NSUserDefaults standardUserDefaults] synchronize];
// Snippet used to get your highscore from the prefs.
highScore = [[[NSUserDefaults standardUserDefaults] objectForKey:#"HighScore"] intValue ];
I have an object at the root of plist that stores objects and keys (one of which is input from a user textfield). I have no problem writing and creating structure; it's trying to read values that causing problem. Below code I used to write the data, can someone tell me how to read the string [val] and [myKey]?
thank you!
#define defaultValue #"Your Name"
#define myKey #"PersonName"
- (void)textFieldAction:(id)sender {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *val;
// Get the new value from the textfield
val = [myTextField stringValue];
if ([val isEqualToString:defaultValue]) {
[defaults removeObjectForKey:myKey];
} else {
// [defaults setObject:val forKey:myKey];
NSDictionary *my_dict = [NSDictionary dictionaryWithObjectsAndKeys:
#"Name", #"PersonName",
#"Email", #"PersonEmail",
#"Dept", #"PersonDept",
#"Job", #"PersonJob",
val, myKey,
#"Status", #"PersonStatus",
nil];
[defaults setObject: my_dict forKey: #"Person"];
[[NSUserDefaults standardUserDefaults] registerDefaults:my_dict];
I would like to automatically populate the textfield with the [val], for [myKey], if the user has the info already in the plist. Here's the code I'm trying to use for that:
- (void)applicationDidFinishLaunching:(NSNotification *)notification {
NSUserDefaults *defaults = [[NSUserDefaults standardUserDefaults] objectForKey:myKey];
NSString *val = [defaults stringForKey:myKey];
if (val == nil) val = defaultValue;
[myTextField setStringValue:val];
You can write the value into NSUserDefault like the following:
[[NSUserDefaults standardUserDefaults] setValue:[myTextField stringValue] forKey:#"Person"];
And read it later like the following:
[myTextField setStringValue:[[NSUserDefaults standardUserDefaults] stringForKey:#"Person"];
So you can simplify your code into:
- (void)textFieldAction:(id)sender {
[[NSUserDefaults standardUserDefaults] setValue:[myTextField stringValue] forKey:#"Person"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
You can set a default value with the registerDefaults:. And when you can retrieve that value simply by calling:
- (void)applicationDidFinishLaunching:(NSNotification *)notification
{
// ...
[[NSUserDefaults standardUserDefaults] registerDefaults:#{#"Person", defaultValue}]
NSString *value = [[NSUserDefaults standardUserDefaults] stringForKey:#"Person"];
[myTextField setStringValue:value];
// ...
}
If I understand correctly, you should be able to do what you need by simply doing:
NSString * val = [[NSUserDefaults standardUserDefaults] objectForKey: myKey];
[textfield setText: val];
NSUserDefaults Reference Page
myTextField.text = [[NSUSerDefaults standardUserDefaults] objectForKey:myKey];