UILabel text not being stored in NSUserDefault - ios

Question

I have a UILabel called 'labelA'. In this label is the letter 'A'.
When I am using NSUserDefault and start my app, the label is empty, but I don't know why?
Here is my ViewController.m file:
- (void)viewDidLoad {
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
self->labelA.text = [defaults objectForKey:#"labelAtext"]; }
- (void)defaults {
NSString *textLabelA = labelA.text;
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:textLabelA forKey:#"labelAtext"];
[defaults synchronize];
}
Here is my NSString in the ViewController.h file
NSString *textLabelA =#"A";
When i load my app without NSUserDefault the labelA.text = A.
does anybody know what's my problem. Thanks a lot :-)

Answer 1

Your method defaults is not being called anywhere, so the text value is never stored in NSUserDefaults.
[self defaults]; // This needs to be called somewhere before you try and access NSUserDefaults.
You should also be accessing self using dot notation, not ->
self.labelA.text = [defaults objectForKey:#"labelAText"];
-> is for dereferencing a struct in C, for more information - What is "->" in Objective C?

Answer 2

When you use UserDefaults. You should first test if you get a value as if the value doesnt exist you need to set it or not.
NSString * myPreference = #"labelAtext";
- (void)viewDidLoad {
NSUserDefaults* userDefault = [NSUserDefaults standardUserDefaults];
id labelValue = [userDefault objectForKey:myPreference];
if (labelValue) // if preference exist
self.labelA.text = labelValue; // set ur label
else
[self storeDefaultValue]; // you store a default value
}
- (void)storeDefaultValue
{
NSString *myDefaultValue = nil;
if ([self.labelA.text isNotEqualToString:#""]) // if ur label not empty
myDefaultValue = self.labelA.text;
else
myDefaultValue = #"Not Available"; // or whatever defaults value you want
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:myDefaultValue forKey:myPreference];
[defaults synchronize];
}
What do you really want to achieve as I don't really understand whats the point of storing a value in preference as soon as you load your app. Give more details on what is your goal.