How to turn flashlight ON and OFF in swift?

Question

I\'d like to add flashlight functionality to my app in Swift. How can I go about doing that?

Answer 1

For swift 3

func toggleFlash() {
    if let device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo), device.hasTorch {
        do {
            try device.lockForConfiguration()
            let torchOn = !device.isTorchActive
            try device.setTorchModeOnWithLevel(1.0)
            device.torchMode = torchOn ? .on : .off
            device.unlockForConfiguration()
        } catch {
            print("error")
        }
    }
}

Answer 2

For xcode 9.1, swift 4 (updated to not crash if no torch):

   func toggleFlash() {
    let device = AVCaptureDevice.default(for: AVMediaType.video)

    if (device != nil) {
        if (device!.hasTorch) {
            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)
            }
        }
    }
}

Answer 3

Solution For Swift 4 With Condition torch is available or not

 func flashlight() {
            guard let device = AVCaptureDevice.default(for: AVMediaType.video) else{
                return
            }
            if (device.hasTorch) {
                    do {
                        try device.lockForConfiguration()
                        if (device.torchMode == .on) {
                            device.torchMode = .off
                        } else {
                            device.torchMode = .on

                        }
                        device.unlockForConfiguration()
                    } catch {

                        print("Torch could not be used")
                        print(error)
                    }
                }
            else{
                print("Torch is not available")
            }
        }

The Solution is Combination of @Joshua Dance And @Lance

Answer 4

I've updated @Lyndsey Scott's great answer for Swift 2.0

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

Answer 5

Updated Swift 4 Answer:

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

    do {
        try device.lockForConfiguration()
        device.torchMode = on ? .on : .off                    
        device.unlockForConfiguration()
    } catch {
        print("Torch could not be used")
    }
}

Then to actually turn it on or off, call the function and pass in a true or false boolean.

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

I got this answer from Hacking with Swift, however their example had an error in it.

They used AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo) but this produces an error saying defaultDevice doesn't exist. So I changed it to AVCaptureDevice.default(for: AVMediaType.video)