The Core iOS Developer’s Cookbook, Fifth Edition

Working with Switches and Steppers

The UISwitch object offers a simple on/off toggle that lets users choose a Boolean value. The switch object contains a single (settable) value property, called on. This property returns either YES or NO, depending on the current state of the control. You can programmatically update a switch’s value by changing the property value directly or calling setOn:animated:, which offers a way to animate the change:

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- (void)didSwitch:(UISwitch *)theSwitch {     self.title = [NSString stringWithFormat:@"%@"         theSwitch.on ? @"On" : @"Off"]; } - (void)viewDidAppear:(BOOL)animated {     [super viewDidAppear:animated];     // Create the switch     UISwitch *theSwitch = [[UISwitch alloc] ...