How to show/hide button with switch that saves value in NSUserDefaults

Question

I have UISwitch named sosSwitch thas saves value in NSUserDefaults key: MySwitch and I have UIButton named sosBtn. How can I show/hide sosBtn depending on the switch value that was saved in NSUserDefaults? And where I need to put the code? In viewDidLoad? Thank you!

Answer 1

Assuming that you already have:

@property (retain, nonatomic) IBOutlet UIButton *sosBtn;
@property (retain, nonatomic) IBOutlet UISwitch *sosSwich;
- (IBAction)sosSwitch:(id)sender;

Try this:

-(void)viewDidLoad
{    
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"MySwitch"])
    {
        self.sosBtn.hidden = NO;
        [self.sosSwich setOn:YES animated:YES]; 
    }
    else 
    {
        self.sosBtn.hidden = YES;
        [self.sosSwich setOn:NO animated:YES];
    }
}

- (IBAction)sosSwitch:(id)sender 
{
    UISwitch *mySosSwitch = (UISwitch *)sender;
    if (mySosSwitch.on)
    {
        self.sosBtn.hidden = NO;
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"MySwitch"];  //YES means sosBtn should be visible
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
    else 
    {
        self.sosBtn.hidden = YES;
        [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"MySwitch"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
}