Question

If one uses interface builder to drag a Switch to a xib-file, the state can be set to on/off in IB. Is there a way to save the state of the switch until next time the app starts so that the switch is in the same state previous to being closed?

Answer 1

you may save it using NSUserDefaults.

first connect your switch as an IBOutlet

@property (weak, nonatomic) IBOutlet UISwitch *mySwitch;

Also connect your switch as an IBAction, event type “Value Changed”

- (IBAction)switched:(id)sender;

then in your UIViewController’s viewDidLoad

BOOL savedState = [[NSUserDefaults standardUserDefaults] boolForKey:@"mySwitch"];
[self.mySwitch setOn:savedState];

and in the new switched: action

- (IBAction)switched:(id)sender
{
    if (sender == self.mySwitch)
    {
        [[NSUserDefaults standardUserDefaults] setBool:self.mySwitch.isOn forKey:@"mySwitch"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
}

hope this helps.