FaceID调用的几个注意点

Posted 2022-06-20 axman

1. 要获取当前系统是否支持FaceID或TouchID,一定要在

LAContext的canEvaluatePolicy条件下，否则常为空，简单说context还没有初始化。

//
//  ViewController.swift
//  FaceIDDemo
//
//  Created by axman.wang on 2017/11/9.
//  Copyright © 2017年 axman.wang. All rights reserved.
//

import UIKit
import LocalAuthentication


//AuthenticationFunctionClass
class AuthenticationWithFaceID
    static let localizedReasonStr = "FaceID方式验证";
    static  func authenticate(complate:@escaping(Error?)->())
        let context = LAContext()
    
        var authError: NSError? = nil
        
        if(context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &authError))
            if context.biometryType != .typeFaceID 
                complate(NSError(domain:"AuthenticationWithFaceID.authenticate",code:0,userInfo:["result":"FaceID is not supported！"]))
                return
            
            context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics,localizedReason: localizedReasonStr,reply: (success, error) -> Void in
                if success 
                    complate(nil)
                else
                    complate(error)
                
            )
        else
            complate(authError)
        
        
    


class ViewController: UIViewController 

    @IBOutlet weak var faceidBnt: UIButton!
    @IBAction func onBntPress(_ sender: UIButton) 
        AuthenticationWithFaceID.authenticate(error) in
            if error == nil
                let alert = UIAlertController(title: "提示", message: "认证成功！", preferredStyle: .alert)
                let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
                alert.addAction(okAction)
                self.present(alert, animated: true, completion: nil)
             else
                let alert = UIAlertController(title: "提示", message: error?.localizedDescription, preferredStyle: .alert)
                let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
                alert.addAction(okAction)
                self.present(alert, animated: true, completion: nil)
            
        
    
    
    override func viewDidLoad() 
        super.viewDidLoad()
    


    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    

2.一定要在info.plist中设置Privacy-Face ID Usage Description，否则一直提示该应用没有为FaceID优化。