I have an array in my app delegate.In some other class I am adding few dictionaries in this app delegate array.
There only I set this appdelegate array for a key in NSUserDefaults.Later on when I check NSUserDefaults value for key for which I saved the appdelegate array, always shows zero object.
I am using
[[NSUserDefaults standardUserDefaults] setObject:app.testArray forKey:#"theKey"];
You can try this code. I am very sure that it will work for you.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:yourArray forKey:#"init_val"];
[defaults synchronize];
For Retrieving Data You Should Use The Following Code :
NSMutableArray *newArray=[[[NSUserDefaults alloc] objectForKey:#"init_val"] mutableCopy];
Hope this helps you.
Try this for retrieving data
NSMutableArray *newArray=[[NSUserDefaults standardUserDefaults] objectForKey:#"init_val"];
Use object for key instead of valueforkey eg: [userdefaults objectForKey:#"init_val"];
Related
I'm storing all my data in NSUserDefaults.
Now I'm trying to store some keys with a specific prefix in an Array. Therefore, I first load the UserDefaults in a Dictionary.
NSString *myPrefix = #"prefix";
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *dict = [defaults dictionaryRepresentation];
for (NSString *keyWithPrefix in dict.keyEnumerator) {
if ([keyWithPrefix hasPrefix: myPrefix]) {
[relevantKeys addObject: keyWithPrefix];
}
}
The Problem is: when I print "dict" (which represents UserDefaults). There are some keys missing.
Does NSUserDefaults delete keys, that are not needed temporarily?
Nope it does not, NSUserDefault is a persistance storage,
Please read the following answer it has a very good explanation
How persistent is [NSUserDefaults standardUserDefaults]?
No, but are you calling [NSUserdefaults synchronize] when you are updating them ?
You should probably be using -synchronize method when storing what you want. i,e:
[[NSUserDefaults standardUserDefaults] setValue:someDictionary forKey:#"someKey"];
[[NSUSerDefaults standardUserDefaults] synchronize];
I am trying to do following task
[[NSUserDefaults standardUserDefaults] setObject:#"Dry" forKey:#"vesselType_preference"];
[[NSUserDefaults standardUserDefaults] synchronize];
where my "vesselType_preference" is multivalue attribute, but it is not getting effected. Please help this is working for other type of attribute but not working for multivalue type.
Thanks
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if (![defaults objectForKey:#"vesselType_preference"])
{
[defaults setObject:#"Dry" forKey:#"vesselType_preference"];
}
[[NSUserDefaults standardUserDefaults] synchronize];
This should work.
NSUserDefaults can only handle objects of NSDictionary, NSData, NSArray, NSString and BOOL. (There might be another in there, not sure) If you need to store a multiple value object like an array or dictionary, I would store your settings there first, then save that to the defaults.
Your code looks fine for storing information to the user defaults. Just make sure you have your object type specified before saving. (id) will not work... or won't work properly.
I'm trying to create an application, and in that I'm receiving some contents from net and loading into and array, if I quit and run the app again i'm losing the data. How can I store the data in the app itself. Should I use some kind of database? If so which one and how can I implement that? I need to store only some string variables.
EDIT:
My app is tabbar based app, and have two tabs. Loading the arrays in one tab and loading that array in a table in the other VC. once I load the array and move to the second tab, the table is loaded with the array. If i go back and add few more values and then if i check, the added datas is not displayed in the table. And also, when I quit the app the table lose all the values, I need to keep the values in the table, even after i quit the app. How can I do that?
here is my code:
in viewdidload:
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
[simplePlistDb setBool:YES forKey:#"isItWorking"];
[simplePlistDb setObject:alertList forKey:#"myArray"];
[simplePlistDb synchronize];
in cellforrowatindexpath:-
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
BOOL flag = [simplePlistDb boolForKey:#"isItWorking"];
if (flag)
{
NSArray *myArray = [simplePlistDb objectForKey:#"myArray"];
for (NSString *str in myArray){
NSLog(#"Str:%#", str);
[loadArray addObject:str];
}
cell.textLabel.text = [loadArray objectAtIndex:indexPath.row];
}
Thank you.
You will want to look into Core Data if you want to save a decent amount of data to the iPhone. However, if not, you can just load the items in the array into a plist and load them from there at launch.
Plist Writing: How to create a new custom property list in iPhone Applications
CoreData: http://www.raywenderlich.com/934/core-data-tutorial-getting-started
Edit--->
As Nekto said, you can also use NSUserDefaults, but I advise mainly using NSUserDefaults for simple NSStrings and integers.
I think for your purposes NSUserDefaults will be enough : NSUserDefaults Class Reference.
Examples:
// save
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
[simplePlistDb setBool:YES forKey:#"isItWorking"];
[simplePlistDb setObject:[NSArray arrayWithObjects:#"very", #"cool", nil]];
[simplePlistDb synchronize];
// restore
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
BOOL flag = [simplePlistDb boolForKey:#"isItWorking"];
if (flag)
{
NSArray *myArray = [simplePlistDb objectForKey:#"myArray"];
for (NSString *str in myArray)
NSLog(#"%#", str);
}
You can use NSUserDefaults in order to store your data till the time your app is installed in your device.
How to write in NSuserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:#"yourObject1" forKey:#"correspopndingKey1"];
[defaults setObject:#"yourObject2" forKey:#"correspopndingKey2"];
[defaults synchronize];
How to read from NSuserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *temp1 = [defaults objectForKey:#"correspopndingKey1"];
NSString *temp2 = [defaults objectForKey:#"correspopndingKey2"];
You can store NSArray in a similar way.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:objArray forKey:#"correspopndingKey"];
[defaults synchronize];
I have the following code in my initialization (first time) of my app:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=#"1";
[defaults setObject:uid forKey:#"init_val"];
[defaults synchronize];
Much later in the code (in response to a button press) I check the value using:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *initVal=[defaults objectForKey:#"init_val"];
initVal is always nil. I have checked and init_val is set up exactly the same in my settings bundle as another field that I can set and read from without issue (they are both set up with a single field named "Key".
#mlewis54:
You can try this code. I am very sure that it will work for you.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=#"1";
[defaults setObject:uid forKey:#"init_val"];
[defaults synchronize];
For Retrieving Data You Should Use The Following Code :
NSString *initVal=[[NSUserDefaults standardUserDefaults] valueForKey:#"init_val"];
OR
NSString *initVal=[[NSUserDefaults standardUserDefaults] objectForKey:#"init_val"];
EDIT:
If still it gives nil, then you can use the following code:
NSString *initVal=[NSString stringWithFormat:#"%#",[[NSUserDefaults standardUserDefaults] valueForKey:#"init_val"]];
OR
NSString *initVal=[NSString stringWithFormat:#"%#",[[NSUserDefaults standardUserDefaults] objectForKey:#"init_val"]];
Hope this helps you.
Decelare this at an event on click of button ...
NSUserDefaults *savedData = [NSUserDefaults standardUserDefaults];
[savedData setObject:userEmailTextField.text forKey:#"userid"];
and on load load the data and check the value you have entered is showing or not...
userEmailTextField.text =[[NSUserDefaults standardUserDefaults]objectForKey:#"userid"];
You need to use the line
NSString *initVal = [defaults stringForKey:#"init_val"];
- since it's a String you must use stringForKey. You can similarly use boolForKey to get a boolean value.
There's nothing wrong in your code, i tried to copy it in my project and it worked good,
so your error could be probably when you check initVal...
what's the code you use to see if initVal is nil?
and are you sure that when/where you check initVal, that var/oblect is still visible ?
try to insert this immediately after your reading code:
NSLog(#"____text read in pref: %#", initVal);
it writes this in my console window -> __text read in pref: 1
of course it's an NSString, i hope you keep it in mind it's not an int or a NSNumber when you check it...
luca
It might be that the initialisation isn't happening. Put an NSLog in there to check it's executed.
It works fine for me with the same code:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *uid=#"1";
[defaults setObject:uid forKey:#"init_val"];
[defaults synchronize];
NSUserDefaults *defaultss = [NSUserDefaults standardUserDefaults];
NSString *initVal=[defaultss objectForKey:#"init_val"];
NSLog(#"Value of initVal: %#",initVal);
O/P on console: Value of initVal: 1
So try to do it with the same code with print on console.
Are you sure you properly initialize NSUserDefaults? When I initialize, in my app delegate, I always create the default user defaults by creating a dictionary of the default values then:
[[NSUserDefaults standardUserDefaults] registerDefaults:appDefaults];
Where appDefaults is the dictionary. Then you should be able to access them correctly.
I am getting user details from .net web server.
I place all these in an array.
Now i need to place these array values in NSuserdefaults.
i try like this.
to store
NSUserDefaults *prefs=[NSUserDefaults standardUserDefaults];
[prefs setObject:resultData forKey:#"agentinfo"];
[prefs synchronize];
to get
NSUserDefaults *prefs=[NSUserDefaults standardUserDefaults];
[prefs arrayForKey:#"agentinfo"]
i am getting details like this
970,
Aditya2,
B,
JNTU1,
"Ram#gamil.com"
how can i get individual numbers 970,Aditya2...
Because i need to Assign them to label.
can any one pls help me.
Thank u in advance
stringForKey will always return nil if the object associated with the provided key is no string. Try arrayForKey instead.
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
if (standardUserDefaults)
yourArray = [standardUserDefaults objectForKey:#"agentinfo"];
use this code for access the array.