操作手电筒(Swift3.0)

1.需要导入AVFoundation模块

2.获取手机摄像头

    // 1.获取摄像头
    guard let captureDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo) else {return}

3.通过摄像头获取硬件的控制权

// 2.获取设备的控制权
    do {
        try captureDevice.lockForConfiguration()
    } catch {
        print(error)
        return
    }

4.设置手电筒的模式

/*
public enum AVCaptureTorchMode : Int {

    case off
    case on
    case auto
}
*/
    // 打开手电筒
    captureDevice.torchMode = .on
    // 关闭手电筒
    captureDevice.torchMode = .off

5.取消硬件的控制权

    // 3.释放设备的控制权
    //captureDevice.unlockForConfiguration()