IOS fingerprint recognition detailed explanation and example code

IOS fingerprint recognition,Here is a compilation of the knowledge used in the project.

IOS fingerprint recognition Now, when both security and efficiency are required, ordinary passwords can no longer meet our requirements, and fingerprint recognition is born.

Everyone has their own exclusive fingerprint. Where payment is required, we only need to press it with a light button, which avoids the tedious steps of entering passwords and is safer. Moreover, mothers no longer have to worry about us forgetting our password.

In fact, it sounds high-end and very simple to implement, because Apple has already packaged it for us, and we only need simple calls.

1. First, we need to import the header file:

#import <LocalAuthentication/>

2. Next, we need to determine whether our device supports fingerprint recognition (iPhone5s+, iOS8.0+)

Next, just determine whether the current user is the owner. It’s over, is it so easy.

- (IBAction)biologyAction:(id)sender {
  
  LAContext *context = [[LAContext alloc] init];
  NSError *error = nil;
  NSString *reason = @"We need to verify your fingerprint to confirm your identity";
  
  // Determine whether the settings support fingerprint recognition (iPhone5s+, iOS8+ support)  if([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&amp;error]){
    
    // Fingerprint recognition only determines whether the current user is the owner    [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:reason reply:^(BOOL success, NSError * _Nullable error) {
      if(success){
        NSLog(@"Fingerprint authentication succeeded");
      }
      else{
        NSLog(@"Fingerprint authentication failed");
        NSLog(@"Error code: %zd",);
        NSLog(@"Error message: %@",error);
        // Error code        // -1: Three consecutive fingerprint recognition errors        // -2: The Cancel button was clicked in the TouchID dialog box        // -3: Click the Enter Password button in the TouchID dialog box        // -4: The TouchID dialog box is cancelled by the system, such as pressing the Home or Power button        // -8: Five consecutive fingerprint recognition errors, the TouchID function is locked, and the next time you need to enter the system password      }
    }];
  }
  else{
    NSLog(@"TouchID device is not available");
    NSLog(@"Error code: %zd",);
    NSLog(@"Error message: %@",error);
  }
}

The following is a code corresponding to Swift 3.0. I won’t talk about the principle. Just like the above, it just translates the OC code into Swift 3.0.

import UIKit
import LocalAuthentication

class ViewController: UIViewController {
  
  override func viewDidLoad() {
    ()
  }
  
  @IBAction func yanzhengAction(_ sender: AnyObject) {
    
    let context = LAContext()
    let reason = "We need your fingerprint to verify your identity"
    var error:NSError?
    
    if (, error:&amp;error){
      (, localizedReason: reason, reply: { (isSuc, error) in
        if isSuc{
          print("Fingerprint verification succeeded")
        }
        else{
          print("Fingerprint verification failed")
          print("error message：\(error)")
          // Error code          // -1: Three consecutive fingerprint recognition errors          // -2: The Cancel button was clicked in the TouchID dialog box          // -3: Click the Enter Password button in the TouchID dialog box          // -4: The TouchID dialog box is cancelled by the system, such as pressing the Home or Power button          // -8: Five consecutive fingerprint recognition errors, the TouchID function is locked, and the next time you need to enter the system password        }
      })
    }
    else{
      print("TouchID settings are not supported")
      print("Error code：\(error!.code)")
      print("error message：\(error)")
    }
  }
}

Thank you for reading, I hope it can help you. Thank you for your support for this site!