https://www.cnblogs.com/ljmaque/p/TouchID.html
最近在项目中刚好用到了TouchId指纹解锁功能，之前也没有接触过，立马百度看看究竟是要如何使用，发现其实也不是很复杂。
文章后面有封装的工具方法，可以直接copy使用。
下面开始跟大家分享一下：
一、使用要点：
（1）需要导入库 LocalAuthentication.framework
（2）引入头文件 #import <LocalAuthentication/LocalAuthentication.h>
（3）指纹解锁只支持iOS 8及以上的版本
（4）如果指纹验证多次错误会被锁定，只能通过输入手机密码来重新启用。iOS 9 提供了一个方法，可以直接调起密码输入界面。
（5）所有操作必须要回到主线程，因为系统的验证是在子线程。
（6）所有的错误处理是通过一个枚举来判断处理的，具体作用看注释
二、代码要点
（1）这是判断系统版本是否大于iOS 8
if (!(MQ_CURRENT_DEVICE_SYSTEM_VERSION >= 8.0)) {
result(NO, MQ_TOUCHID_ERROR_SYSTEM_NOT_SUPPORT);
return;
}
（2）判断是否可用
// 返回bool值 [authenContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]
3）下面的就是重要的点 :
指纹解锁多次失败以后，系统会锁定TouchID硬件必须通过输入手机密码来解锁，如果系统是iOS8的话，TouchID被锁定以后只能通过重启手机来重新开启。
//系统提供的两个验证的枚举
typedef NS_ENUM(NSInteger, LAPolicy)
{
LAPolicyDeviceOwnerAuthenticationWithBiometrics NS_ENUM_AVAILABLE(NA, 8_0) __WATCHOS_AVAILABLE(3.0) __TVOS_AVAILABLE(10.0) = kLAPolicyDeviceOwnerAuthenticationWithBiometrics,
LAPolicyDeviceOwnerAuthentication NS_ENUM_AVAILABLE(10_11, 9_0) = kLAPolicyDeviceOwnerAuthentication
} NS_ENUM_AVAILABLE(10_10, 8_0) __WATCHOS_AVAILABLE(3.0) __TVOS_AVAILABLE(10.0);
kLAPolicyDeviceOwnerAuthentication 这个值只有在iOS9.0及以后才可以使用，利用这个值可以调出输入密码来解锁TouchID的界面。
[authenContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
localizedReason:TOUCHID_NOTICE_MESSAGE
reply:^(BOOL success, NSError * _Nullable error) {
if (success) {
//已经重新解锁Touchid
}
}];
开始指纹解锁代码
[authenContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
localizedReason:TOUCHID_NOTICE_MESSAGE
reply:^(BOOL success, NSError * _Nullable error) {
if (success) {
// 解锁成功
}
}];
（4）看看系统的错误枚举
typedef NS_ENUM(NSInteger, LAError)
{
/// Authentication was not successful, because user failed to provide valid credentials.
LAErrorAuthenticationFailed = kLAErrorAuthenticationFailed,
/// Authentication was canceled by user (e.g. tapped Cancel button).
LAErrorUserCancel = kLAErrorUserCancel,
/// Authentication was canceled, because the user tapped the fallback button (Enter Password).
LAErrorUserFallback = kLAErrorUserFallback,
/// Authentication was canceled by system (e.g. another application went to foreground).
LAErrorSystemCancel = kLAErrorSystemCancel,
/// Authentication could not start, because passcode is not set on the device.
LAErrorPasscodeNotSet = kLAErrorPasscodeNotSet,
/// Authentication could not start, because Touch ID is not available on the device.
LAErrorTouchIDNotAvailable NS_ENUM_DEPRECATED(10_10, 10_13, 8_0, 11_0, "use LAErrorBiometryNotAvailable") = kLAErrorTouchIDNotAvailable,
/// Authentication could not start, because Touch ID has no enrolled fingers.
LAErrorTouchIDNotEnrolled NS_ENUM_DEPRECATED(10_10, 10_13, 8_0, 11_0, "use LAErrorBiometryNotEnrolled") = kLAErrorTouchIDNotEnrolled,
/// 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_DEPRECATED(10_11, 10_13, 9_0, 11_0, "use LAErrorBiometryLockout")
__WATCHOS_DEPRECATED(3.0, 4.0, "use LAErrorBiometryLockout") __TVOS_DEPRECATED(10.0, 11.0, "use LAErrorBiometryLockout") = 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,
/// Authentication could not start, because biometry is not available on the device.
LAErrorBiometryNotAvailable NS_ENUM_AVAILABLE(10_13, 11_0) __WATCHOS_AVAILABLE(4.0) __TVOS_AVAILABLE(11.0) = kLAErrorBiometryNotAvailable,
/// Authentication could not start, because biometry has no enrolled identities.
LAErrorBiometryNotEnrolled NS_ENUM_AVAILABLE(10_13, 11_0) __WATCHOS_AVAILABLE(4.0) __TVOS_AVAILABLE(11.0) = kLAErrorBiometryNotEnrolled,
/// Authentication was not successful, because there were too many failed biometry attempts and
/// biometry is now locked. Passcode is required to unlock biometry, e.g. evaluating
/// LAPolicyDeviceOwnerAuthenticationWithBiometrics will ask for passcode as a prerequisite.
LAErrorBiometryLockout NS_ENUM_AVAILABLE(10_13, 11_0) __WATCHOS_AVAILABLE(4.0) __TVOS_AVAILABLE(11.0) = kLAErrorBiometryLockout,
/// Authentication failed, because it would require showing UI which has been forbidden
/// by using interactionNotAllowed property.
LAErrorNotInteractive API_AVAILABLE(macos(10.10), ios(8.0), watchos(3.0), tvos(10.0)) = kLAErrorNotInteractive,
} NS_ENUM_AVAILABLE(10_10, 8_0) __WATCHOS_AVAILABLE(3.0) __TVOS_AVAILABLE(10.0);
三、这是我封装的工具类
（1）MQTouchID.h文件
//
// MQTouchID.h
// Test
//
// Created by PasserMontanus on 2018/3/21.
// Copyright ? 2018年 lgl. All rights reserved.
//
#import <Foundation/Foundation.h>
typedef NS_ENUM(NSInteger, MQ_TOUCHID_ERROR) {
// 系统不支持 要大于 8.0
MQ_TOUCHID_ERROR_SYSTEM_NOT_SUPPORT = 0,
// 验证成功
MQ_TOUCHID_ERROR_SUCCESS = 1,
// 系统取消授权，如其他APP切入
MQ_TOUCHID_ERROR_SYSTEM_CANCEL = -4,
// 用户取消验证Touch ID
MQ_TOUCHID_ERROR_USER_CANCEL = -2,
// 用户选择输入密码
MQ_TOUCHID_ERROR_USER_FALLBACK = -3,
//授权失败
MQ_TOUCHID_ERROR_FAILED = -1,
//系统未设置密码 这个密码在用户指纹多次验证失败的时候要用他来重新激活
MQ_TOUCHID_ERROR_PASSCODE_NOT_SET = -5,
//设备Touch ID不可用，例如未打开
MQ_TOUCHID_ERROR_NOT_AVAILABLE = -6,
//设备Touch ID不可用，用户没有录入指纹
MQ_TOUCHID_ERROR_NOT_ENROLLED = -7,
//身份验证失败，因为它需要显示已被禁止的UI
MQ_TOUCHID_ERROR_NOT_INTERACTIVE = -1004,
// 设备Touch ID被锁定，输入错误的次数过多 这个时候需要密码来重新激活
MQ_TOUCHID_ERROR_LOCKOUT = -8 ,
//应用程序已取消身份验证
MQ_TOUCHID_ERROR_APP_CANCEL = -9,
// 传递给此调用的LAContext先前已失效。
MQ_TOUCHID_ERROR_INVALID_CONTEXT = -10
};
typedef void(^MQTouchIDResult)(BOOL isSuccess, MQ_TOUCHID_ERROR error_code);
@interface MQTouchID : NSObject
/**
开始验证 TouchID 指纹解锁 （需要导入 LocalAuthentication.framework）
注意: 结果回调以后的操作都需要回到主线程 这个验证是在子线程里面执行的
*/
+ (void)validateTouchID:(MQTouchIDResult)result;
@end
（2）MQTouchID.m文件
//
// MQTouchID.m
// Test
//
// Created by PasserMontanus on 2018/3/21.
// Copyright ? 2018年 lgl. All rights reserved.
//
#import "MQTouchID.h"
#import <LocalAuthentication/LocalAuthentication.h>
#define MQ_CURRENT_DEVICE_SYSTEM_VERSION ([[UIDevice currentDevice]systemVersion].doubleValue)
static NSString * TOUCHID_NOTICE_MESSAGE = @"通过Home键验证已有的手机指纹";
static NSString * TOUCHID_NOTICE_RESTART_MESSAGE = @"重新开启TouchID功能";
@implementation MQTouchID
+ (void)validateTouchID:(MQTouchIDResult)result {
if (!(MQ_CURRENT_DEVICE_SYSTEM_VERSION >= 8.0)) {
result(NO, MQ_TOUCHID_ERROR_SYSTEM_NOT_SUPPORT);
return;
}
LAContext *authenContext = [[LAContext alloc]init];
NSError* error = nil;
if ([authenContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) { // 可用
[self startValidateTouchID:authenContext result:result];
} else { // 不可用
MQ_TOUCHID_ERROR erroCode = [self errorCode:error.code];
[self processingTouchIdError:authenContext erroCode:erroCode result:result];
}
}
+ (void)startValidateTouchID:(LAContext *)authenContext result:(MQTouchIDResult)result {
[authenContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
localizedReason:TOUCHID_NOTICE_MESSAGE
reply:^(BOOL success, NSError * _Nullable error) {
if (success) {
result(YES,MQ_TOUCHID_ERROR_SUCCESS);
} else {
MQ_TOUCHID_ERROR erroCode = [self errorCode:error.code];
[self processingTouchIdError:authenContext erroCode:erroCode result:result];
}
}];
}
+ (void)processingTouchIdError:(LAContext *)authenContext
erroCode:(MQ_TOUCHID_ERROR)erroCode
result:(MQTouchIDResult)result {
if (@available(iOS 9.0, *)) {
if (erroCode == MQ_TOUCHID_ERROR_LOCKOUT) {
[authenContext evaluatePolicy:LAPolicyDeviceOwnerAuthentication
localizedReason:TOUCHID_NOTICE_RESTART_MESSAGE
reply:^(BOOL success, NSError * _Nullable error) {
if (success) {
[self validateTouchID:result];
} else {
result(NO, MQ_TOUCHID_ERROR_USER_CANCEL);
}
}];
} else {
result(NO, erroCode);
}
} else {
result(NO, erroCode);
}
}
+ (MQ_TOUCHID_ERROR)errorCode:(NSInteger )errorCode {
switch (errorCode) {
case LAErrorSystemCancel:{ // 系统取消授权，如其他APP切入
return MQ_TOUCHID_ERROR_SYSTEM_CANCEL;
break;
}
case LAErrorUserCancel:{ // 用户取消验证Touch ID
return MQ_TOUCHID_ERROR_USER_CANCEL;
break;
}
case LAErrorUserFallback:{ // 用户选择输入密码
return MQ_TOUCHID_ERROR_USER_FALLBACK;
break;
}
case LAErrorAuthenticationFailed:{ // //授权失败
return MQ_TOUCHID_ERROR_FAILED;
break;
}
case LAErrorPasscodeNotSet: { //系统未设置密码 这个密码在用户指纹多次验证失败的时候要用他来重新激活
return MQ_TOUCHID_ERROR_PASSCODE_NOT_SET;
break;
}
case LAErrorTouchIDNotAvailable: { //设备Touch ID不可用，例如未打开
return MQ_TOUCHID_ERROR_NOT_AVAILABLE;
break;
}
case LAErrorTouchIDNotEnrolled: { //设备Touch ID不可用，用户没有录入指纹
return MQ_TOUCHID_ERROR_NOT_ENROLLED;
break;
}
case LAErrorNotInteractive: { // 身份验证失败，因为它需要显示已被禁止的UI
return MQ_TOUCHID_ERROR_NOT_INTERACTIVE;
break;
}
default:{
if (@available(iOS 9.0, *)) {
if (errorCode == LAErrorTouchIDLockout) { // 设备Touch ID被锁定，输入错误的次数过多 这个时候需要密码来重新激活
return MQ_TOUCHID_ERROR_LOCKOUT;
break;
} else {
if (errorCode == LAErrorInvalidContext) {
return MQ_TOUCHID_ERROR_INVALID_CONTEXT;
break;
} else if (errorCode == LAErrorAppCancel) {
return MQ_TOUCHID_ERROR_APP_CANCEL;
break;
} else {
return MQ_TOUCHID_ERROR_FAILED;
break;
}
}
} else {
return MQ_TOUCHID_ERROR_FAILED;
break;
}
}
}
}
@end
四、最后结语
（1）最后的结果回调以后的操作一定要在主线程，系统验证在子线程进行
（2）以上就是我的一点小总结，欢迎大家指正。