How to Turn Flashlight on and Off in Swift

How to turn flashlight ON and OFF in swift?

Update #1: (torchActive isn't returning the expected value; perhaps because it's been modified)

Update #2: For Swift 2.0

To toggle the flash from on to off (not just "on" as in mad pig's answer), you can use the following method:

func toggleFlash() {
    let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    if (device.hasTorch) {
        do {
            try device.lockForConfiguration()
            if (device.torchMode == AVCaptureTorchMode.On) {
                device.torchMode = AVCaptureTorchMode.Off
            } else {
                do {
                    try device.setTorchModeOnWithLevel(1.0)
                } catch {
                    print(error)
                }
            }
            device.unlockForConfiguration()
        } catch {
            print(error)
        }
    }
}

I used nested do-catch blocks to implement Awesomeness's suggestion from the comments. This way, even if try device.setTorchModeOnWithLevel(1.0) fails, the device is properly unlocked for configuration.

Update #3: For Swift 4:

(I edited the code a bit to my personal taste)

func toggleFlash() {
    guard let device = AVCaptureDevice.default(for: AVMediaType.video) else { return }
    guard device.hasTorch else { return }

    do {
        try device.lockForConfiguration()

        if (device.torchMode == AVCaptureDevice.TorchMode.on) {
            device.torchMode = AVCaptureDevice.TorchMode.off
        } else {
            do {
                try device.setTorchModeOn(level: 1.0)
            } catch {
                print(error)
            }
        }

        device.unlockForConfiguration()
    } catch {
        print(error)
    }
}

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Original answer:

To toggle the flash from on to off (not just "on" as in mad pig's answer), you can use the following method:

func toggleFlash() {
    let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    if (device.hasTorch) {
        device.lockForConfiguration(nil)
        let torchOn = !device.torchActive
        device.setTorchModeOnWithLevel(1.0, error: nil)
        device.torchMode = torchOn ? AVCaptureTorchMode.On : AVCaptureTorchMode.Off
        device.unlockForConfiguration()
    }
}

Can not get the Flashlight to turn ON or OFF in my app - Swift

Yeah, you are just defining a function inside an @ibaction function but you never call it. What you can do is define your function outside of the @ibaction and call it when the button is pressed :

import AVFoundation

func toggleFlash(on: Bool) {
    guard let device = AVCaptureDevice.default(for: .video) else { return }

    if device.hasTorch {
        do {
            try device.lockForConfiguration()

            if on == true {
                device.torchMode = .on
            } else {
                device.torchMode = .off
            }

            device.unlockForConfiguration()
        } catch {
            print("Torch could not be used")
        }
    } else {
        print("Torch is not available")
    }
}

@IBAction func toggleFlash(_ sender: UIButton) {
    toggleFlash(on: true)
    //If you want to set it off just call toggleFlash(on : Falsse)
}

Changing iPhone flashlight intensity over time (Swift)

Use the function setTorchModeOnWithLevel to set the level, you can use a timer to set times when the level will change.

Here's an example of how to do this (implemented in the AppDelegate of a brand-new iOS Single View Application):

  var timer: NSTimer?

  func applicationDidBecomeActive(application: UIApplication) {
    timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "delayedAction", userInfo: nil, repeats: true)
  }

  let maxLightLevel = 5
  var lightLevel = 5

  func delayedAction() {
    guard let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
      else {
        timer?.invalidate()
        return
    }
    if let _ = try? device.lockForConfiguration() {
      defer { device.unlockForConfiguration() }
      if lightLevel == 0 {
        timer?.invalidate()
        device.torchMode = .Off
      }
      else {
        try! device.setTorchModeOnWithLevel(Float(lightLevel)/Float(maxLightLevel))
      }
      --lightLevel
    }
  }

This code is just a rough example and should have appropriate behaviors added to handle switching apps, thrown exceptions, and so on.

Keep torch on while taking video iOS swift

Call this method

Inside your camera active/Open func or When device camera active -

   func flashActive() {
    if let currentDevice = AVCaptureDevice.default(for: AVMediaType.video), currentDevice.hasTorch {
        do {
            try currentDevice.lockForConfiguration()
            let torchOn = !currentDevice.isTorchActive
            try currentDevice.setTorchModeOn(level:1.0)//Or whatever you want
            currentDevice.torchMode = torchOn ? .on : .off
            currentDevice.unlockForConfiguration()
        } catch {
            print("error")
        }
    }
}

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

@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()
    }
}

How to turn on/offf camera flash light with ARKit?

func toggleTorch(on: Bool) {
        guard let device = AVCaptureDevice.default(for: AVMediaType.video) 
        else {return}

        if device.hasTorch {
            do {
                try device.lockForConfiguration()

                if on == true {
                    device.torchMode = .on // set on
                } else {
                    device.torchMode = .off // set off
                }

                device.unlockForConfiguration()
            } catch {
                print("Torch could not be used")
            }
        } else {
            print("Torch is not available")
        }
    }

Call this as

toggleTorch(on: true) of toggleTorch(on: false)

ref: Hacking with Swift

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