NEW! Master Swift design patterns with my latest book! >>

How to turn on the camera flashlight to make a torch

Paul Hudson       @twostraws

There is one simple property required to enable or disable a device's torch, but you do need to put in some wrapper code to make it work safely. Specifically, you need to use the lockForConfiguration() and unlockForConfiguration() methods of the AVCaptureDevice class in order to make sure only one app can control the torch at a time.

You will need to import the AVFoundation framework, because that's where the AVCaptureDevice class comes from. Once that's done, add this function to your code and you're good to code:

func toggleTorch(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")
    }
}

With that, you can now turn the torch on like this:

toggleTorch(on: true)

Available from iOS 6.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Learn Swift faster!

Take your Swift learning to the next level: buy the Hacking with Swift e-book and get bonus material to help you learn faster!

MASTER SWIFT NOW
Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Practical iOS 11 Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Click here to visit the Hacking with Swift store >>