• Priority queue and binary heap


    The cause is the title of a weekly game 1705 Maximum number of apples to eat There is a special apple tree, which can grow several apples every day for n days. On day I, apples [i] apples will grow on the tree. These apples will rot and become inedible after days [i] (that is, […]

  • How to install win10 in MAC system? Two methods of installing win10 on MAC


    How to install win10 on Mac? For Windows users, it’s easy to install win10 on the original basis, but for Apple Mac users, if you want to install win10 on the Mac, it’s troublesome. The following Xiaobian will introduce the method of installing win10 on the Mac. Xiaobian will introduce two methods with you. If […]

  • Comparison of mobile end cross platform schemes


    Cross platform technology classification Hybrid (ionic, vant, wechat applet) JavaScript development + native rendering (react native, weex) Self drawn UI + native (QT, fluent) Hybrid hybrid development (H5 + native) The principle of this kind of framework is to realize part of the content that needs to be dynamically changed in the app through H5, […]

  • Explain the front-end development process based on react + Redux with examples


    In the current front-end industry, react and Redux are developing in full swing. The number of stars of react in GitHub is 42000 +, which exceeds 39000 + of jQuery, and will soon exceed 49000 + of angular 1, which is popular in previous years; The star number of Redux is also close to 20000, […]

  • Principle of Apple’s dual verification of IOS


    为什么要做双重验证? debug模式下,安装包不需要上传到App Store,可以直接安装到手机上。苹果为了保证系统的安全性,又必须对安装的APP有绝对的控制权。APP必须经过苹果允许才可以安装,不能被滥用导致非开发APP也能被安装。为了实现这些需求,iOS签名的复杂度也就开始增加了,苹果这里给出的方案是双层签名。 双重代码签名的实现流程 图1 说明: iOS的双层代码签名流程这里简单梳理一下,这也不是最终的iOS签名原理。iOS的最终签名在这个基础上还要稍微加点东西。 首先这里有两个角色。一个是iOS系统 还有一个就是我们的Mac系统,因为iOS的APP开发环境在Mac系统下,所以这个依赖关系成为了苹果双层签名的基础。 步骤: 1.在Mac系统中生成非对称加密算法的一对公钥\私钥(你的Xcode帮你代办了).这里称为公钥M 私钥M 。 M = Mac 2.苹果自己有固定的一对公私钥,跟之前App Store原理一样,私钥在苹果后台,公钥在每个iOS系统中.这里称为公钥A , 私钥A. A=Apple 3.把公钥M 以及一些你开发者的信息,传到苹果后台(这个就是CSR文件),用苹果后台里的私钥 A 去签名公钥M。得到一份数据包含了公钥M 以及其签名,把这份数据称为证书。 4.在开发时,编译完一个 APP 后,用本地的私钥 M(今后你导出的P12) 对这个 APP 进行签名,同时把第三步得到的证书一起打包进 APP 里,安装到手机上。 5.在安装时,iOS 系统取得证书,通过系统内置的公钥 A,去验证证书的数字签名是否正确。 6.验证证书后确保了钥 M 是苹果认证过的,再用公钥 M 去验证 APP 的签名,这里就间接验证了这个 APP 安装行为是否经过苹果官方允许。(这里只验证安装行为,不验证APP 是否被改动,因为开发阶段 APP 内容总是不断变化的,苹果不需要管。) 注意:以上的操作会存在一个重大的bug,苹果是绝对不允许这样的事情发生的。就是这样子操作的话我们可以不经过苹果的服务器生成证书,自己进行验证就可以安装APP,所以就引申出了描述文件。 描述文件 描述文件(Provisioning profile)一般包括三样东西:证书、App ID、设备信息、权限信息。当我们在真机运行或者打包一个项目的时候,证书用来证明我们程序的安全性和合法性。 […]

  • The Bluetooth connection of Apple Mac OS X Yosemite system has a delay problem


    It was reported on the morning of October 24 that on the official support forum of apple, some users reported that after upgrading to the OS X Yosemite system, there were various problems with the Bluetooth function. Yosemite caused a variety of Bluetooth related problems, including Apple‘s own hardware. Some users said, including Apple’s own […]

  • Function recursion


    WeChat official account is searching for the program yuan Xiaozhuang. It pays attention to how to develop a family breadwinner by python. introduce Functions can be defined or called nested. Nested definition refers to defining another function inside a function when defining a function; Nested call refers to calling another function inside a function in […]

  • iOS MultipeerConnectivity


    problem Undertake the above [IOS WiFi transmission], what if you remove the LAN? Can file transfer between devices be realized Common methods of data transmission between IOS devices: 1. Bluetooth 2.airdrop 3.MultipeerConnectivity This article focuses on multipeerconnectivity Serve Device as server Have a peerid to mark yourself lazy var me: MCPeerID = { let peer […]

  • Realize content sharing between IOS apps


    preface There are several common ways for us to share content between different apps on IOS platform: The first is throughAirDropRealize the sharing of documents and data between apps of different devices; The second is to define a URL scheme for each app, and directly access an app by accessing a URL with a specified […]

  • Browser “alliance”! Apple / Google / Mozilla / Microsoft work together to solve the problem of Web “interoperability”


    Recently, the four major browser manufacturers apple, Google, Mozilla and Microsoft, as well as software consulting companies bocoup and igalia, have agreed to work together to improve the interoperability and user experience of their web browsers and make the performance of web design technology more consistent on different platforms. The organization created a benchmark called […]

  • After IOS 14.5 +, cocoaasyncsocket UDP broadcast, multicast and scan failed — perfect solution


    The project used cocoaasyncsocket. Before establishing TCP, UDP broadcast was used to obtain the IP address and configure the network for the device. However, after the system was upgraded to IOS 14.5, it was found that an iPad could receive the broadcast intermittently, but the iPhone had not received the broadcast. Even when sending multicast, […]

  • CRMEB Pro v1. 2. Detailed steps of quick packaging app


    Shopping mall shopping mall CRMEB Pro is a H5/ official account / small program mall system. Its backend development has used the most popular technologies at present, such as asynchronous tasks, database link pools, form generation, long connection, task queue, timing task, front end separation, Redis cache, etc. the front end is also developed by […]