简单实现iOS指纹解锁(TouchID)

//iOS8.0后才支持指纹识别接口 if ([UIDevice currentDevice].systemVersion.floatValue < 8.0) {  return; }

- (void)evaluateAuthenticate{ //创建LAContext LAContext* context = [[LAContext alloc] init]; NSError* error = nil; NSString* result = @"请验证已有指纹";  //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:     {      //系统取消授权，如其他APP切入      break;     }     case LAErrorUserCancel:     {      //用户取消验证Touch ID      break;     }     case LAErrorAuthenticationFailed:     {      //授权失败      break;     }     case LAErrorPasscodeNotSet:     {      //系统未设置密码      break;     }     case LAErrorTouchIDNotAvailable:     {      //设备Touch ID不可用，例如未打开      break;     }     case LAErrorTouchIDNotEnrolled:     {      //设备Touch ID不可用，用户未录入      break;     }     case LAErrorUserFallback:     {      [[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  NSLog(@"不支持指纹识别");    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); }}