I have a feeling there is a simple way to do this. I have a number between 1 and 100 and it is stored in a variable called firstValue. This variable is then put into a UILabel. When the user exits my app, I want this firstValue to be saved so that when the app is loaded by the user this number can be re-inserted into the UILabel (firstValueLabel.text).
Many thanks,
Stuart
You can use NSUserDefaults for this.
To save it:
NSInteger myValue = ...; // This is your number
NSString *key = ... ; // This is a string to identify your number
[[NSUserDefaults standardUserDefaults] setInteger:myValue forKey:key];
To read it:
NSInteger myValue = [[NSUserDefaults standardUserDefaults] integerForKey:key];
If no previous value has been saved, the value returned will be 0.
Add this to your applicationWillTerminate:
[[NSUserDefaults standardUserDefaults] synchronize];
you can use the NSUserDefaults to store some variable for your application to retrieve them after a close of the application.
For exemple:
// Set the name of the view
[[NSUserDefaults standardUserDefaults] setInteger:10 forKey:#"firstValue"];
To retrieve the last action of the user:
// Retrieve the last view name
Integer firstValue = [[NSUserDefaults standardUserDefaults] integerForKey:#"firstValue"];
But you can add other than a integer. (see the NSUserDefaults Class Reference)
Related
I need to save a variable that increments every time a user hits a button within the app. I've been trying to do that with NSUserDefaults with no success. Here's the code I'm using:
[[NSUserDefaults standardUserDefaults] setInteger:i++ forKey:#"AppCount"];
When I output this in the log, however, I keep getting 0.
Any help would be greatly appreciated.
Try adding:
[[NSUserDefaults standardUserDefaults] synchronize];
After each time you change the value of your integer.
Quoting Apple's documentation on synchronize:
Writes any modifications to the persistent domains to disk and updates
all unmodified persistent domains to what is on disk.
http://developer.apple.com/library/ios/DOCUMENTATION/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/Reference/Reference.html#//apple_ref/occ/instm/NSUserDefaults/synchronize
So with this modification, your final code should look like this:
[[NSUserDefaults standardUserDefaults] setInteger:i++ forKey:#"AppCount"];
[[NSUserDefaults standardUserDefaults] synchronize];
EDIT: Actually on second thought, give this a try:
I think the problem is using i++ assumes that the application will always be able to keep track of the count, and every time you re-enter the application i gets reset.
The following works, I just tested it.
if (![[NSUserDefaults standardUserDefaults] integerForKey:#"AppCount"]) {
[[NSUserDefaults standardUserDefaults] setInteger:i forKey:#"AppCount"];
}else{
[[NSUserDefaults standardUserDefaults] setInteger:[[NSUserDefaults standardUserDefaults] integerForKey:#"AppCount"] + 1 forKey:#"AppCount"];
}
[[NSUserDefaults standardUserDefaults] synchronize];
You can use Static NSUIInteger appCount=0;
in the function user taps increase it value appCount++;
that keeps the value in function calls within the app. after app closing you write it to file.
- (void)viewDidLoad {
[super viewDidLoad];
countFirst= [[NSUserDefaults standardUserDefaults]integerForKey:#"Counter"];
countFirst++;
}
Write this wherever you want to increment.
[[NSUserDefaults standardUserDefaults] setInteger:countFirst++ forKey:#"Counter"];
Hello everyone I would have a value for the need to save every time I press a button (count), virtually every time a user presses a button in my app should be pressed to keep count of the times (1,2,3,4, etc. etc.) the problem is that that data would be permanently saved, that is, even when you exit the app or restart the device should be saved on the iphone to find it and increase it reopened after the application.
Is there an easier way to CoreData or SqlLite to do this?
thanks
Here is a sample code:
To store it:
[[NSUserDefaults standardUserDefaults] setInteger: intCount forKey:#"Count"];
[[NSUserDefaults standardUserDefaults] synchronize];
To read it:
intCount = [[NSUserDefaults standardUserDefaults] integerForKey: #"Count"];
The easiest way would be use NSUserDefaults to do this, no need for a bigger data store if it's only an integer.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
int buttonCount = 0;
// Do you count somewhere and add to buttonCount
[defaults setObject:[NSNumber numberWithInt:buttonCount] forKey:#"buttonPress"];
and to retrieve to number back just use
int buttonPress = [[[NSUserDefaults standardUserDefaults] objectForKey:#"buttonPress"] intValue];
NSUserDefaults is the solution. Update the stored value in every button click....
I have some data that's been stored using NSUserDefaults in one view and then being displayed in another view. The issue I'm having is that when the user changes the data and then returns to the view where the data is displayed (in a UILabel), the data that was first saved is displayed instead of the newer saved text.
I think I need to do something with viewDidAppear perhaps, so that every time the view appears the newest saved data is displayed.
here's the code that Im displaying the NSUserDefaults stored info on a UILabel:
NSString *aValue = [[NSUserDefaults standardUserDefaults] objectForKey:#"myTextFieldKey"];
NSLog(#"Value from standardUserDefaults: %#", aValue);
NSLog(#"Label: %#", myLabel);
myLabel.text = aValue;
if someone could point me in the right direction that would be great,
thanks
Put this text in
- (void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear: animated];
NSString *aValue = [[NSUserDefaults standardUserDefaults] objectForKey:#"myTextFieldKey"];
NSLog(#"Value from standardUserDefaults: %#", aValue);
NSLog(#"Label: %#", myLabel);
myLabel.text = aValue;
}
And in your "edit" view in - viewWillDisappear: save changes in NSUserDefaults
When saving data to NSUserDefaults, it doesnt immediately write to the Persistent Storage. When you save data in NSUserDefaults, make sure you call:
[[NSUserDefaults standardUserDefaults] synchronize];
This way, the value(s) saved will immediately be written to Storage and each subsequent read from the UserDefaults will yield the updated value.
Do not forget the use synchronize when you set some value
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:YOUR_VALUE forKey:#"KEY_NAME"];
[defaults synchronize];
Now you can place your code in viewWillAppear method to retrieve the value from defaults, this will help you fetch the currentsaved value for your desired key.
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
NSString* strValue = [defaults objectForKey:#"KEY_NAME"];
myLabel.text = strValue != nil ? strValue : #"No Value";
Hope it helps
In Swift we can do it following way:
To save value:
let defaults = UserDefaults.standard
defaults.set(YOUR_VALUE, forKey: "YOUR_KEY_NAME")
To get value:
let defaults = UserDefaults.standard
let data = defaults.objectForKey("YOUR_KEY_NAME")
For more details visit:
https://www.hackingwithswift.com/example-code/system/how-to-save-user-settings-using-userdefaults
Been working on some code streamlining and have realised that it would be really helpful if my app had a preferences system.
Now here's how my code works.
A method runs based upon an integer stored in NSUserDefaults
e.g.
if ([[NSUserDefaults standardUserDefaults] integerForKey:#"scifi1"] == 040){
[self spaceDown];
}
else if ([[NSUserDefaults standardUserDefaults] integerForKey:#"scifi1"] == 10040){
[self ctrldown];
[self spaceDown];
}
Now what I want to do is when I exit the view (via a specific button) is to dump the value of #"scifi1" into a new preference, say for example - an integer named #"savedscifi1"
Now I know how to save integers into NSUserDefaults,
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setInteger:VALUEHERE forKey:#"savedscifi1"];
[userDefaults synchronize];
However - I'm not sure how I can substiture in the value of scifi1 instead of (in this case) 'VALUEHERE' - can anyone help with this? I feel it's really simple but I can't help but think I'm being a bit thick...sleep deprived and approaching a deadline! I know I can't just call up #"scifi1"but beyond that....??
NSInteger value = [[NSUserDefaults standardUserDefaults] integerForKey: ...];
[[NSUserDefaults standardUserDefaults] setInteger: value forKey: ...];
i wana store the index of seleted cell of table using NSArray, can u help me....
You can use user defaults or property list for this.
Example on user defaults. You have a controller class that has access to the index and will load it at startup and write it into plist whenever it's updated:
If you have some kind of controller class then you would put this code into + (void)initialize, it initialises the variable if it does not exists in plist:
+ (void)initialize
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *appDefaults =
[NSDictionary dictionaryWithObject:[NSNumber numberWithInteger:5]
forKey:#"MyFunnyIndex"];
[defaults registerDefaults:appDefaults];
}
In your -(void)awakeFromNib (I'm assuming you're using some kind of controller class) load your last stored value:
-(void)awakeFromNib
{
int index =
[[NSUserDefaults standardUserDefaults] integerForKey:#"MyFunnyIndex"];
[somethingThatNeedsIndex setIndex:index];
// ...
}
Somewhere where the index is updated (or where you want to write it to plist), let's call it - (void)updateInterface:
- (void)updateInterface
{
[[NSUserDefaults standardUserDefaults]
setObject:[NSNumber numberWithInteger:index]
forKey:#"MyFunnyIndex"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
I don't know if I understand the question correctly, but it sounds like you could use a property list to store this information. Property lists are very easy to use and quite efficient with small amounts of data.
Read the "Property List Programming Guide" for further explanation. There is even a tutorial in there.