在 Swift 中打开/关闭 iPhone LED（闪光灯）？ [复制]

Posted 2023-02-23

【中文标题】在 Swift 中打开/关闭 iPhone LED（闪光灯）？ [复制]

【英文标题】：Turn the iPhone LED (flash) on/off in Swift? [duplicate]

【发布时间】：2015-03-11 23:43:11

【问题描述】：

我可以使用什么代码通过一个按钮打开/关闭 iPhone 闪光灯（在 Swift 中）。

我是使用 Outlet 还是 Action 进行连接？

感谢所有帮助！

【参考方案1】：

Xcode 9 测试版 • Swift 4

import AVFoundation
extension AVCaptureDevice 
    var isLocked: Bool 
        do 
            try lockForConfiguration()
            return true
         catch 
            print(error)
            return false
        
    
    func setTorch(intensity: Float) 
       guard hasTorch && isLocked else  return 
        defer  unlockForConfiguration() 
        if intensity > 0 
            if torchMode == .off 
                torchMode = .on
            
            do 
                try setTorchModeOn(level: intensity)
             catch 
                print(error)
            
         else 
            torchMode = .off
        
    

---

用法：

import UIKit
import AVFoundation

class ViewController: UIViewController 
    var device: AVCaptureDevice!
    override func viewDidLoad() 
        super.viewDidLoad()
         device = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .unspecified)
    
    @IBAction func slider(_ sender: UISlider) 
        device.setTorch(intensity: sender.value)
    

---

Xcode 8.2.1 • Swift 3.0.2

extension AVCaptureDevice 
    @discardableResult
    class func toggleTorch() -> Bool 
        guard let defaultDevice = AVCaptureDevice.defaultDevice(withDeviceType: .builtInWideAngleCamera, mediaType: AVMediaTypeVideo, position: .unspecified)
        else 
            print("early exit")
            return false
        
        // Check if the default device has torch
        if  defaultDevice.hasTorch 
            print("defaultDevice.hasTorch:", defaultDevice.hasTorch)

            // Lock your default device for configuration
            do 
                // unlock your device when done
                defer 
                    defaultDevice.unlockForConfiguration()
                    print("defaultDevice.unlockedForConfiguration:", true)
                
                try defaultDevice.lockForConfiguration()
                print("defaultDevice.lockedForConfiguration:", true)
                // Toggles the torchMode
                defaultDevice.torchMode = defaultDevice.torchMode == .on ? .off : .on
                // Sets the torch intensity to 100% if torchMode is ON
                if defaultDevice.torchMode == .on 
                    do 
                        try defaultDevice.setTorchModeOnWithLevel(1)
                     catch 
                        print(error.localizedDescription)
                    
                
             catch 
                print(error.localizedDescription)
            
        
        print("defaultDevice.torchMode:", defaultDevice.torchMode == .on)
        return defaultDevice.torchMode == .on
    

---

class ViewController: UIViewController 
    override func viewDidLoad() 
        super.viewDidLoad()
        view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(tap(_:))))
    
    func tap(_ gesture: UITapGestureRecognizer) 
        if AVCaptureDevice.toggleTorch() 
            print("TORCH IS ON")
         else 
            print("TORCH IS OFF")
        
    
    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.