I save a bool value in NSUserDefaults like this:
[[NSUserDefaults standardUserDefaults]setBool:NO forKey:#"password"];
And then I synchronize defaults like this:
[[NSUserDefaults standardUserDefaults]synchronize];
But when my app enters background and then enters foreground my bool changes value to YES
Why does that happen ? I set my bool to YES only in one place in program, which is not managing when my app leaves/enters foreground.
Thanks!
Just perform a simple test where you are saving your bool as
[[NSUserDefaults standardUserDefaults]setBool:NO forKey:#"password"];
[[NSUserDefaults standardUserDefaults]synchronize];
NSLog(#"%d",[[NSUserDefaults standardUserDefaults] boolForKey:#"password"]);
see what's the value..
Your retrieval code should look something like this.
if(![[NSUserDefaults standardUserDefaults] boolForKey:#"password"]) {
//False
} else {
//True
}
Make sure you have the right key string (#"password" in your case) when you retrieve the boolean value. It is case sensitive.
[[NSUserDefaults standardUserDefaults] boolForKey:#"password"];
Do a text search in your whole project for this key and you will find the offending code.
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....
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 need to track the download of a certain iphone application. I tried a lot and found out that we could track it from the AppStore. But i need to track that from my application itself. So please help me to identify the method that fires when the application starts for the first time. Thanks.
There's no specific method that fires only on the 1st application launch. You can set a flag in user defaults on application start - so if the flag is not present then that will mean that application launched for the 1st time:
- (void)applicationDidFinishLaunching:(UIApplication *)application {
if (![[NSUserDefaults standardDefaults] boolForKey:#"AlreadyLaunched"]){
// First launch logic
[[NSUserDefaults standardDefaults] setBool:YES forKey:#"AlreadyLaunched"];
[[NSUserDefaults standardDefaults] synchronize];
}
...
}
But i need to track that from my application itself.
No.
But if you really want to do this you could use something like this:
BOOL hasUsedSpyWareFunctions = [[NSUserDefaults standardUserDefaults] boolForKey:#"SpyWareKey"];
if (!hasUsedSpyWareFunctions) {
[self spyOnUser];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:#"SpyWareKey"];
}
if you are a Pro in spying you only set the key to YES if the method returned successfully (ie a network connection could be established)
There’s no such an event, at least not one that I know of. But what you want can be trivially done using NSUserDefaults. Simply check for some boolean flag and if it’s not there, it’s a first run and you can set the flag:
NSString *const AlreadyRunKey = #"already-run";
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if (![prefs boolForKey:AlreadyRunKey]) {
[prefs setBool:YES forKey:AlreadyRunKey];
[prefs synchronize];
// do whatever else you want
}
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)