判斷iOS機器是否支持TouchId, FaceId

說明

iPhone X 以後支持Face ID， iPhone 5S以後支持Touch ID. 怎麼準確判斷機器是否支持，Face ID或者Touch ID呢？ 實際上系統有方法判斷，但是如果沒有註冊Face ID或者Touch ID，判斷結果也是none

解決方法

用swift 5來解決

import Foundation
import LocalAuthentication

extension LAContext {
    enum BiometricType: String {
        case none
        case touchID
        case faceID
    }

    var biometricType: BiometricType {
        var error: NSError?

        guard self.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
            // Capture these recoverable error through fabric
            return .none
        }

        if #available(iOS 11.0, *) {
            switch self.biometryType {
            case .touchID:
                return .touchID
            case .faceID:
                return .faceID
            default:
                return .none
            }
        }

        return self.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil) ? .touchID : .none
    }

}

調用方法

// need to import LocalAuthentication in the calling file
// import LocalAuthentication

let currentType = LAContext().biometricType
print("biometry type > \(currentType)")
// biometry type > touchID

如果用模擬器來調試，需要開啓Touch ID或者Face ID已經註冊。設置路徑如下
Simulator > Hardware > Touch ID/Face ID > Enrolled.

參考

https://stackoverflow.com/questions/46887547/how-to-programmatically-check-support-of-face-id-and-touch-id/62299672#62299672