How can we programmatically change the brightness of the iPhone screen? - iphone

Question

How can I change the brightness of the screen programmatically using iPhone SDK?

Answer 1

[[UIScreen mainScreen] setBrightness: yourvalue];
Requires iOS 5.0 or later. yourvalue is a float between 0.0 and 1.0.

Answer 2

UPDATE: For Swift 3
UIScreen.main.brightness = YourBrightnessValue
Here's the swift answer to perform this
UIScreen.mainScreen().brightness = YourBrightnessValue
YourBrightnessValue is a float between 0.0 and 1.0

Answer 3

I had some problems with changing the screen brightness in viewDidLoad/viewWillDisappear so I created a singleton class to handle all the action. This is how I do it:
import Foundation
import UIKit
final class ScreenBrightnessHelper {
private var timer: Timer?
private var brightness: CGFloat?
private var isBrighteningScreen = false
private var isDarkeningScreen = false
private init() { }
static let shared = ScreenBrightnessHelper()
func brightenDisplay() {
resetTimer()
isBrighteningScreen = true
if #available(iOS 10.0, *), timer == nil {
brightness = UIScreen.main.brightness
timer = Timer.scheduledTimer(withTimeInterval: 0.01, repeats: true) { (timer) in
UIScreen.main.brightness = UIScreen.main.brightness + 0.01
if UIScreen.main.brightness > 0.99 || !self.isBrighteningScreen {
self.resetTimer()
}
}
}
timer?.fire()
}
func darkenDisplay() {
resetTimer()
isDarkeningScreen = true
guard let brightness = brightness else {
return
}
if #available(iOS 10.0, *), timer == nil {
timer = Timer.scheduledTimer(withTimeInterval: 0.01, repeats: true) { (timer) in
UIScreen.main.brightness = UIScreen.main.brightness - 0.01
if UIScreen.main.brightness < brightness || !self.isDarkeningScreen {
self.resetTimer()
self.brightness = nil
}
}
timer?.fire()
}
}
private func resetTimer() {
timer?.invalidate()
timer = nil
isBrighteningScreen = false
isDarkeningScreen = false
}
}