iOS指紋識別

iOS指紋識別比較簡單，主要由LAContontext類中的兩種方法完成：
1. - (BOOL)canEvaluatePolicy:(LAPolicy)policy error:(NSError * autoreleasing *)error __attribute((swift_error(none))) 檢測設備是否支持指紋識別；
2. - (void)evaluatePolicy:(LAPolicy)policy
localizedReason:(NSString *)localizedReason
reply:(void(^)(BOOL success, NSError * __nullable error))reply 識別指紋

代碼：

LAContext *context = [LAContext new];
    context.localizedCancelTitle = @"取消";
    context.localizedFallbackTitle = @"密碼登錄";
    NSError *error = nil;
    BOOL supportFingerPrint = [context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error];
    if (!supportFingerPrint) {
        NSLog(@"不支持指紋解鎖:%@",error.localizedDescription);
        switch (error.code) {
            case LAErrorTouchIDNotEnrolled:
                NSLog(@"TouchID Not Enrolled");
                break;
            case LAErrorPasscodeNotSet:
                NSLog(@"Password Not Set");
                break;

            default:
                NSLog(@"TouchID Not Available");
                break;
        }
    } else {
        NSLog(@"支持指紋解鎖");
        [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"指紋解鎖" reply:^(BOOL success, NSError * _Nullable error) {
            if(success) {
                NSLog(@"指紋解鎖成功");
            } else {
                switch (error.code) {
                    case LAErrorAuthenticationFailed: {
                        NSLog(@"Authentication Failed");
                    }
                        break;
                    case LAErrorUserCancel: {
                        NSLog(@"User Canceled");
                    }
                        break;
                    case LAErrorUserFallback: {
                        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                            NSLog(@"User Fallback");
                        }];
                    }
                        break;
                    case LAErrorSystemCancel: {
                        NSLog(@"System Cancel");
                    }
                        break;
                    case LAErrorPasscodeNotSet: {
                        NSLog(@"Password Not Set");
                    }
                        break;
                    case LAErrorTouchIDNotAvailable: {
                        NSLog(@"TouchID Not Available");
                    }
                        break;
                    case LAErrorTouchIDNotEnrolled: {
                        NSLog(@"TouchID Not Enrolled");
                    }
                    default: {
                        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                            NSLog(@"Other Targat ");
                        }];
                    }
                        break;
                }
            }
        }];

    }