UISwitch

UISwitch is a UIControl in UIKit that provides a two-state on/off switch. It is used to toggle boolean options in iOS apps, and it communicates state changes through the target-action mechanism, typically in response to the valueChanged event.

Appearance and customization: The control consists of a rounded track and a sliding thumb. When on, the track is colored by onTintColor and the thumb can be tinted with thumbTintColor. It can also display simple icons via onImage and offImage. The overall size is determined by the system, and the control is usable in Interface Builder as well as programmatically.

API and usage: The current state is exposed through the isOn property. You can set it programmatically with setOn(_:animated:), read it with isOn, and respond to changes by adding a target for the .valueChanged event. Typical usage involves initializing the switch, configuring its initial state, and handling user interaction to enable or disable related features.

Swift example: let switchControl = UISwitch(); switchControl.isOn = true; switchControl.addTarget(self, action: #selector(switchChanged(_:)), for: .valueChanged)

Notes: UISwitch is a standard UIKit control designed for consistency with system settings screens. It is suitable for many forms and preference interfaces, but for highly customized visual designs, developers may opt for alternative controls or custom implementations. Accessibility is supported, with the control announced as a switch by assistive technologies and reflecting its on/off state to users.