如何将整数值保存到NSuserDefault，如sqlite？

Question

I want to save and retrieve value in NSUserDefault. I am saving and retrieving Value sucessfully. But when I go cak Homepage and again come in my class The value is not stored and all the process done again. It doesnot Remember old value.

I am doing this-

-(void)ViewDidLoad{
    A = 0;                // int A; defone in .h
    [self calling_Once];
}

-(void)calling_Once{
     NSLog(@"A is: %d",A);     // A is always zero when I leave this class and return Back to this class. This is my only problem. I want A=1; when I go back And return to this class but 
     NSInteger B = [[NSUserDefaults standardUserDefaults] integerForKey:@"save_Interger_Value_For_Formula_One"];  //is not able to remeber value. It gives A=0; B =0; When I come back to this class, I want It should return A=1; B=1; and remember old value like sqlite when I return to this class.

     if (A==0) {
         [self refreshButton];
         NSLog(@"Before Increment A is: %d",A);
         A++;

         NSLog(@"After Increment A is: %d",A);

         [[NSUserDefaults standardUserDefaults] setInteger:A forKey:@"save_Interger_Value_For_Formula_One"];
    }

    NSInteger B = [[NSUserDefaults standardUserDefaults] integerForKey:@"save_Interger_Value_For_Formula_One"];
    B = A;

    NSLog(@" B is: %d",B);
    B = A;
    NSLog(@" A is: %d",A);
}

Any Idea or suggestions would be highly welcome.

Answer 1

To save an integer;

[[NSUserDefaults standardUserDefaults] setInteger:number forKey:@"unique_name"];
[[NSUserDefaults standardUserDefaults] synchronize];

To retrieve it;

NSInteger x = [[NSUserDefaults standardUserDefaults] integerForKey:@"unique_name"];

Good luck!

Answer 2

Try to implement like this..Sure it'll help...

@implementation ClassA

- (void)viewDidLoad
    {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        [[NSUserDefaults standardUserDefaults]setInteger:100 forKey:@"save_Interger_Value_For_Formula_One"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    }

@end

@implementation ClassB

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
       int B = [[[NSUserDefaults standardUserDefaults]        integerForKey:@"save_Interger_Value_For_Formula_One"] integerValue];

     NSLog(@"Interger Value %d",b);
}

Answer 3

Just synchronize your NSUserDefaults after inserting value.

[[NSUserDefaults standardUserDefaults] synchronize];  

You can follow this answer How to delete a user default value in NSUserDefaults?

In your code initially you are setting 0 to A, try this

-(void)ViewDidLoad
{
        A = [[NSUserDefaults standardUserDefaults] integerForKey:@"save_Interger_Value_For_Formula_One"];   
      [self calling_Once];
}

Answer 4

NSUserDefaults * def=[NSUserDefaults standardUserDefaults];
    [def setInteger:yourvalue forKey:@"YourKey"];
    [def synchronize];

Try this code....