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

  #pragma mark - 指纹验证
  - (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

            NSLog(@"验证成功");

            

        }

        else

        {

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

            switch (error.code) {

                case LAErrorSystemCancel:

                {

                    NSLog(@"切换到其他APP，系统取消验证Touch IDAuthentication was cancelled by the system");

                    //切换到其他APP，系统取消验证Touch ID

                    break;

                }

                case LAErrorUserCancel:

                {

                    NSLog(@"用户取消验证Touch ID Authentication was cancelled by the user");

                    //用户取消验证Touch ID

                    break;

                }

                case LAErrorUserFallback:

                {

                    NSLog(@"用户选择输入密码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没登录 TouchID is not enrolled");

            break;

        }

        case LAErrorPasscodeNotSet:

        {

            NSLog(@"密码没有设置 A passcode has not been set");

            break;

        }

        default:

        {

            NSLog(@"不支持 TouchID not available");

            break;

        }

    }

    

    NSLog(@"系统错误%@",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