How to turn the iPhone camera flash on/off swift 2? - ios

Question

I was looking how to turn on/off the iPhone's camera flash and I found this:
#IBAction func didTouchFlashButton(sender: AnyObject) {
let avDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// check if the device has torch
if avDevice.hasTorch {
// lock your device for configuration
avDevice.lockForConfiguration(nil)
// check if your torchMode is on or off. If on turns it off otherwise turns it on
if avDevice.torchActive {
avDevice.torchMode = AVCaptureTorchMode.Off
} else {
// sets the torch intensity to 100%
avDevice.setTorchModeOnWithLevel(1.0, error: nil)
}
// unlock your device
avDevice.unlockForConfiguration()
}
}
I do get 2 issues, one on the line:
avDevice.lockForConfiguration(nil)
and the other on the line:
avDevice.setTorchModeOnWithLevel(1.0, error:nil)
both of them are related to exception handling but I don't know how to resolve them.

Answer 1

#IBAction func didTouchFlashButton(sender: UIButton) {
let avDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// check if the device has torch
if avDevice.hasTorch {
// lock your device for configuration
do {
let abv = try avDevice.lockForConfiguration()
} catch {
print("aaaa")
}
// check if your torchMode is on or off. If on turns it off otherwise turns it on
if avDevice.torchActive {
avDevice.torchMode = AVCaptureTorchMode.Off
} else {
// sets the torch intensity to 100%
do {
let abv = try avDevice.setTorchModeOnWithLevel(1.0)
} catch {
print("bbb")
}
// avDevice.setTorchModeOnWithLevel(1.0, error: nil)
}
// unlock your device
avDevice.unlockForConfiguration()
}
}

Answer 2

Swift 4 version, adapted from Ivan Slavov's answer. "TorchMode.auto" is also an option if you want to get fancy.
#IBAction func didTouchFlashButton(_ sender: Any) {
if let avDevice = AVCaptureDevice.default(for: AVMediaType.video) {
if (avDevice.hasTorch) {
do {
try avDevice.lockForConfiguration()
} catch {
print("aaaa")
}
if avDevice.isTorchActive {
avDevice.torchMode = AVCaptureDevice.TorchMode.off
} else {
avDevice.torchMode = AVCaptureDevice.TorchMode.on
}
}
// unlock your device
avDevice.unlockForConfiguration()
}
}

Answer 3

Swift 5.4 &
Xcode 12.4 &
iOS 14.4.2
#objc private func flashEnableButtonAction() {
guard let captureDevice = AVCaptureDevice.default(for: AVMediaType.video) else {
return
}
if captureDevice.hasTorch {
do {
let _: () = try captureDevice.lockForConfiguration()
} catch {
print("aaaa")
}
if captureDevice.isTorchActive {
captureDevice.torchMode = AVCaptureDevice.TorchMode.off
} else {
do {
let _ = try captureDevice.setTorchModeOn(level: 1.0)
} catch {
print("bbb")
}
}
captureDevice.unlockForConfiguration()
}
}

Answer 4

for some reason "avDevice.torchActive" is always false, even when the torch is on, making it impossible to turn off but I fixed it by declaring a boolean initially set to false and every time the flash turns on, the boolean is set to true.
var on: Bool = false
#IBAction func didTouchFlashButton(sender: UIButton) {
let avDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// check if the device has torch
if avDevice.hasTorch {
// lock your device for configuration
do {
let abv = try avDevice.lockForConfiguration()
} catch {
print("aaaa")
}
// check if your torchMode is on or off. If on turns it off otherwise turns it on
if on == true {
avDevice.torchMode = AVCaptureTorchMode.Off
on = false
} else {
// sets the torch intensity to 100%
do {
let abv = try avDevice.setTorchModeOnWithLevel(1.0)
on = true
} catch {
print("bbb")
}
// avDevice.setTorchModeOnWithLevel(1.0, error: nil)
}
// unlock your device
avDevice.unlockForConfiguration()
}
}

Answer 5

import AVFoundation
var videoDeviceInput: AVCaptureDeviceInput?
var movieFileOutput: AVCaptureMovieFileOutput?
var stillImageOutput: AVCaptureStillImageOutput?
Add a class method to ViewController.
class func setFlashMode(flashMode: AVCaptureFlashMode, device: AVCaptureDevice){
if device.hasFlash && device.isFlashModeSupported(flashMode) {
var error: NSError? = nil
do {
try device.lockForConfiguration()
device.flashMode = flashMode
device.unlockForConfiguration()
} catch let error1 as NSError {
error = error1
print(error)
}
}
}
Check the flashmode status.
// Flash set to Auto/Off for Still Capture
print("flashMode.rawValue : \(self.videoDeviceInput!.device.flashMode.rawValue)")
if(self.videoDeviceInput!.device.flashMode.rawValue == 1)
{
CameraViewController.setFlashMode(AVCaptureFlashMode.On, device: self.videoDeviceInput!.device)
}
else if (self.videoDeviceInput!.device.flashMode.rawValue == 2)
{
CameraViewController.setFlashMode(AVCaptureFlashMode.Auto, device: self.videoDeviceInput!.device)
}
else
{
CameraViewController.setFlashMode(AVCaptureFlashMode.Off, device: self.videoDeviceInput!.device)
}

Answer 6

Another short way is to do this
let devices = AVCaptureDevice.devices()
let device = devices[0]
guard device.isTorchAvailable else { return }
do {
try device.lockForConfiguration()
if device.torchMode == .on {
device.torchMode = .off
}else{
device.torchMode = .on
}
} catch {
debugPrint(error)
}