beacon

I am building a framework in which I need to import some objective-c frameworks for now I need to import "Beaconstac.framework" but as we can not add a bridging header in a swift framework project so my question is how can I use this framework in my project this is not directly accessible in my project I tried import Beaconstac but its giving error "No Such Module" is there any alternative to do this? You need to import the Beaconstac framework in your umbrella header. That is, if you'd ordinarily use, e.g., #import <Beaconstac/Beaconstac.h> in an Obj-C bridging header, for a framework you

在学习几年编程之后，你会发现所有的问题都没有简单、快捷的解决方案，很多问题都需要权衡和妥协，而本文介绍的就是数据库在并发性能和可串行化之间做的权衡和妥协 - 并发控制机制。 如果数据库中的所有事务都是串行执行的，那么它非常容易成为整个应用的性能瓶颈，虽然说没法水平扩展的节点在最后都会成为瓶颈，但是串行执行事务的数据库会加速这一过程；而并发（Concurrency）使一切事情的发生都有了可能，它能够解决一定的性能问题，但是它会带来更多诡异的错误。 引入了并发事务之后，如果不对事务的执行进行控制就会出现各种各样的问题，你可能没有享受到并发带来的性能提升就已经被各种奇怪的问题折磨的欲仙欲死了。 概述 如何控制并发是数据库领域中非常重要的问题之一，不过到今天为止事务并发的控制已经有了很多成熟的解决方案，而这些方案的原理就是这篇文章想要介绍的内容，文章中会介绍最为常见的三种并发控制机制： 分别是悲观并发控制、乐观并发控制和多版本并发控制，其中悲观并发控制其实是最常见的并发控制机制，也就是锁；而乐观并发控制其实也有另一个名字：乐观锁，乐观锁其实并不是一种真实存在的锁，我们会在文章后面的部分中具体介绍；最后就是多版本并发控制（MVCC）了，与前两者对立的命名不同，MVCC 可以与前两者中的任意一种机制结合使用，以提高数据库的读性能。 既然这篇文章介绍了不同的并发控制机制

I attached data to Eddystone Beacons using The Proximity Beacon API. I want to fetch the Beacon attachments using Nearby Messages API. I followed the steps mentioned at https://developers.google.com/nearby/messages/android/get-beacon-messages . But I am not able to read Beacon attachments. The onFound() method is not getting called Check the following... Set a callback on the response to subscribe and call startResolutionForResult on the Status object if the Status was APP_NOT_OPTED_IN . See github example Make sure you've enabled the Nearby API in the Developer Console for your app. Step 3

Problem: I am getting a GATT exception 133 when trying to read the characteristics. I made a delay to read but unfortunately it doesn't works followed by the GATT 22 error . It happens on few devices but i don't know how to solve this problem. Code: public void performRead() { printMessage("\nperform READ started..."); UUID serviceuid = UUID.fromString(UUID_SERVICE); if (BDA.getmBluetoothGatt() == null) return; BluetoothGattService service = BDA.getmBluetoothGatt().getService( serviceuid); UUID characteristicuid = UUID.fromString(UUID_CHARACTERISTIC_STATUS); BluetoothGattCharacteristic