Touch ID -Objective-C

biometrics.m

LAContext *myContext = [[LAContext alloc] init];
NSError *authError = nil;
NSString *myReasonString = @"String explaining why app needs authentication";

if ([myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError]) {
    [myContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                  localizedReason:myReasonString
                            reply:^(BOOL succes, NSError *error) {
            if (success) {
                // User authenticated successfully
            } else {
                // Authenticate failed
            }
        }];
} else {
    // Could not evaluate policy; check authError
}