iOS touchID 处理办法

iOS 官方 Demo
https://developer.apple.com/library/ios/samplecode/KeychainTouchID/Introduction/Intro.html https://segmentfault.com/a/1190000002516465

基础知识

支持系统和机型

iOS系统的指纹识别功能最低支持的机型为

iPhone 5s

，最低支持系统为

iOS
8

，虽然安装

iOS 7

系统的5s机型可以使用系统提供的指纹解锁功能，但由于

API

并未开放，所以理论上第三方软件不可使用。

依赖框架

LocalAuthentication.framework

#import <LocalAuthentication/LocalAuthentication.h>

注意事项

做

iOS 8

以下版本适配时，务必进行API验证，避免调用相关API引起崩溃。

使用类

LAContext

指纹验证操作对象

代码

- (void)authenticateUser
{
//初始化上下文对象
LAContext* context = [[LAContext alloc] init];
//错误对象
NSError* error = nil;
NSString* result = @"Authentication is needed to access your notes.";

//首先使用canEvaluatePolicy 判断设备支持状态
if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
//支持指纹验证
[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:result reply:^(BOOL success, NSError *error) {
if (success) {
//验证成功，主线程处理UI
}
else
{
NSLog(@"%@",error.localizedDescription);
switch (error.code) {
case LAErrorSystemCancel:
{
NSLog(@"Authentication was cancelled by the system");
//切换到其他APP，系统取消验证Touch ID
break;
}
case LAErrorUserCancel:
{
NSLog(@"Authentication was cancelled by the user");
//用户取消验证Touch ID
break;
}
case LAErrorUserFallback:
{
NSLog(@"User selected to enter custom password");
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
//用户选择输入密码，切换主线程处理
}];
break;
}
default:
{
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
//其他情况，切换主线程处理
}];
break;
}
}
}
}];
}
else
{
//不支持指纹识别，LOG出错误详情

switch (error.code) {
case LAErrorTouchIDNotEnrolled:
{
NSLog(@"TouchID is not enrolled");
break;
}
case LAErrorPasscodeNotSet:
{
NSLog(@"A passcode has not been set");
break;
}
default:
{
NSLog(@"TouchID not available");
break;
}
}

NSLog(@"%@",error.localizedDescription);
}
}

typedef NS_ENUM(NSInteger, LAError)
{
//授权失败
LAErrorAuthenticationFailed = kLAErrorAuthenticationFailed,

//用户取消Touch ID授权
LAErrorUserCancel           = kLAErrorUserCancel,

//用户选择输入密码
LAErrorUserFallback         = kLAErrorUserFallback,

//系统取消授权(例如其他APP切入)
LAErrorSystemCancel         = kLAErrorSystemCancel,

//系统未设置密码
LAErrorPasscodeNotSet       = kLAErrorPasscodeNotSet,

//设备Touch ID不可用，例如未打开
LAErrorTouchIDNotAvailable  = kLAErrorTouchIDNotAvailable,

//设备Touch ID不可用，用户未录入
LAErrorTouchIDNotEnrolled   = kLAErrorTouchIDNotEnrolled,
} NS_ENUM_AVAILABLE(10_10, 8_0);

操作流程

首先判断系统版本，

iOS 8

及以上版本执行

-(void)authenticateUser

方法，方法自动判断设备是否支持和开启

Touch
ID

。

iOS 9

感谢秋儿指出iOS 9加入了三种新的错误类型。

/// Authentication was not successful, because there were too many failed Touch ID attempts and
/// Touch ID is now locked. Passcode is required to unlock Touch ID, e.g. evaluating
/// LAPolicyDeviceOwnerAuthenticationWithBiometrics will ask for passcode as a prerequisite.
LAErrorTouchIDLockout   NS_ENUM_AVAILABLE(10_11, 9_0) = kLAErrorTouchIDLockout,

/// Authentication was canceled by application (e.g. invalidate was called while
/// authentication was in progress).
LAErrorAppCancel        NS_ENUM_AVAILABLE(10_11, 9_0) = kLAErrorAppCancel,

/// LAContext passed to this call has been previously invalidated.
LAErrorInvalidContext   NS_ENUM_AVAILABLE(10_11, 9_0) = kLAErrorInvalidContext

其中，

LAErrorTouchIDLockout

是在8.0中也会出现的情况，但并未归为单独的错误类型，这个错误出现，源自用户多次连续使用Touch ID失败，Touch ID被锁，需要用户输入密码解锁，这个错误的交互

LocalAuthentication.framework

已经封装好了，不需要开发者关心。

LAErrorAppCancel

和

LAErrorSystemCancel

相似，都是当前软件被挂起取消了授权，但是前者是用户不能控制的挂起，例如突然来了电话，电话应用进入前台，APP被挂起。后者是用户自己切到了别的应用，例如按home键挂起。

LAErrorInvalidContext

很好理解，就是授权过程中,LAContext对象被释放掉了，造成的授权失败。

//
//  ViewController.m
//  test_ touch_ID_01
//
//  Created by admin on 2/15/16.
//  Copyright © 2016 jeffasd. All rights reserved.
//

#import "ViewController.h"

#import <LocalAuthentication/LocalAuthentication.h>

@interface ViewController ()

@property(nonatomic, strong) UIButton *authority;
@property(nonatomic, strong) UIButton *entryButton;

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

_authority = [UIButton buttonWithType:UIButtonTypeCustom];
_authority.frame = CGRectMake(100, 100, 200, 50);
_authority.backgroundColor = [UIColor cyanColor];

[_authority setTitle:@"是否支持" forState:UIControlStateNormal];

[_authority addTarget:self action:@selector(canEvaluatePolicy) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:_authority];

}

#pragma mark - evaluatePolicy
- (void)canEvaluatePolicy{

LAContext *context = [LAContext new];
__block NSString *message;
NSError *error;
BOOL success;

success = [context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error];
if (success) {
message = [NSString stringWithFormat:@"Touch ID is available"];
}else{
message = [NSString stringWithFormat:@"Touch ID is not available"];
NSLog(@"%@", message);

switch (error.code) {
case LAErrorTouchIDNotEnrolled:
NSLog(@"TouchID is not enrolled");
break;

case LAErrorPasscodeNotSet:
NSLog(@"A passcode has not been set");
break;

default:
NSLog(@"TouchID not available");
break;
}

NSLog(@"localized %@",error.localizedDescription);
}

NSLog(@"%@", message);
}

- (IBAction)entryButton:(UIButton *)sender {

LAContext *context = [LAContext new];
__block NSString *message;

// Set text for the localized fallback button.
//    context.localizedFallbackTitle = @"Enter Password 111";
//    context.localizedFallbackTitle = @"111";
//    context.localizedFallbackTitle = @"";

//show the authentication UI with our reason string
[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"Unlock access to locked feature" reply:^(BOOL success, NSError * _Nullable authenticationError) {
if (success) {
//验证成功，主线程处理UI
message = @"evaluatePolicy : success";
}else{
message = [NSString stringWithFormat:@"evaluatePolicy %@", authenticationError.localizedDescription];
NSLog(@"%@", message);

NSLog(@"%@",authenticationError.localizedDescription);
switch (authenticationError.code) {
case LAErrorSystemCancel:
{
NSLog(@"Authentication was cancelled by the system");
//切换到其他APP，系统取消验证Touch ID
break;
}
case LAErrorUserCancel:
{
NSLog(@"Authentication was cancelled by the user");
//用户取消验证Touch ID
break;
}
case LAErrorUserFallback:
{
NSLog(@"User selected to enter custom password");
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
//用户选择输入密码，切换主线程处理
UIView *view = [UIView new];
view.frame = self.view.bounds;
view.backgroundColor = [UIColor yellowColor];

[self.view addSubview:view];
}];
break;
}
case LAErrorAuthenticationFailed:
{
NSLog(@"User kLAErrorAuthenticationFailed");
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
//用户选择输入密码，切换主线程处理
}];
break;
}

default:
{
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
//其他情况，切换主线程处理
}];
break;
}
}
}

NSLog(@"%@", message);
}];
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end