avfoundation-camera

AVFoundation 相机模块

Session 架构

Session 类型选择

• Session 所有操作必须在专用串行队列执行
• 禁止在主线程配置 session，预览层更新除外

private let sessionQueue = DispatchQueue(label: "com.app.sessionQueue")

完整权限处理流程

final class CameraPermissionManager {
    static func checkAuthorization(completion: @escaping (Bool) -> Void) {
        let status = AVCaptureDevice.authorizationStatus(for: .video)
        switch status {
        case .authorized:
            completion(true)
        case .notDetermined:
            requestAccess(completion: completion)
        case .denied, .restricted:
            showPermissionDeniedAlert()
            completion(false)
        @unknown default:
            completion(false)
        }
    }

    private static func requestAccess(completion: @escaping (Bool) -> Void) {
        AVCaptureDevice.requestAccess(for: .video) { granted in
            DispatchQueue.main.async {
                if granted {
                    completion(true)
                } else {
                    showPermissionDeniedAlert()
                    completion(false)
                }
            }
        }
    }

    private static func showPermissionDeniedAlert() {
        guard let settingsURL = URL(string: UIApplication.openSettingsURLString) else { return }
        let alert = UIAlertController(
            title: "需要相机权限".localized,
            message: "请在设置中开启相机权限，以使用录制功能".localized,
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "去设置".localized, style: .default) { _ in
            UIApplication.shared.open(settingsURL)
        })
        alert.addAction(UIAlertAction(title: "取消".localized, style: .cancel))
        (UIApplication.shared.connectedScenes.first?.delegate as? SceneDelegate)?
            .window?.rootViewController?.present(alert, animated: true)
    }
}