• What if the iPhone enters the correct password but the prompt is incorrect?


    Generally, after the mobile phone is restarted, we need to enter the password to unlock the mobile phone. But recently, some partners found that the system always prompts incorrectly after entering the lock screen password. How to solve this problem? In fact, this kind of password error may not be caused by the iPhone security […]

  • Differences between exists and in in SQL statements


    select * from A where id in(select id from B) Conclusion: in () is suitable for the situation that the data in table B is smaller than that in table a select a.* from A a where exists(select 1 from B b where a.id=b.id) Exists is used to check whether a subquery will return at […]

  • Six things I learned when I wrote code in Ali


    After years of writing code, I always feel that how to write clean and elegant code is not an easy thing. According to the theorem of 10000 hours of deliberate training, it takes about five years to become a master, assuming that 8 hours a day, 20 days a month, 12 months a year. In […]

  • NPM error


    1.“This is probably not a problem with npm. There is likely additional logging output above. ”resolvent: rm -rf node_modules rm package-lock.json npm cache clear –force npm install 2 “npm ERR! A complete log of this run can be found in: npm ERR! D:\node\node_cache\_logs\2020-06-13T08_12_35_648Z-debug.log” resolvent npm install npm -g NPM install can be installed NPM error […]

  • React native call native: callback (Android)


    In react native, it can be customized in Java layerReactMethod(https://segmentfault.com/a/1190000004486024)This way, native method in Android can be called directly in JavaScript layerBut in most method calls, we need to know what the result is after calling the method and whether there are exceptions. JavaScript itself is an event driven language. Callback method can be used […]

  • Computed property “xxx” was assigned to but it has no setter


    problem V-model value problem Vuex – Computed property “xxx” was assigned to but it has no setter Error reporting <template> <div v-model=”checkStatus”> 123 </div> </template> <script> import {mapState} from “vuex” export default { computed:{ …mapState({ checkStatus:state => state.common.checkStatus }) } } </script> Solution //In your Component computed: { …mapGetters({ nameFromStore: ‘name’ }), name: { get(){ […]

  • How to deal with errors and exceptions in large software projects


    I didn’t find any bugs in the test, so there are no bugs in the system, right? Unfortunately, large-scale software is too complex to be bug free no matter how many tests. You can’t test all the different ways users use the app. Therefore, it is very important to understand the differences between errors and […]

  • JavaScript, CSS layout problem sorting (vertical and horizontal center)


    Source code link codesandboxJS code: parent package app export default function App() { return ( <div className=”Parent”> <div className=”App”> <h1>Hello CodeSandbox</h1> <h2>Start editing to see some magic happen!</h2> </div> </div> ); } Several realization methods of center Method 1, using margin: Auto to achieve .Parent { height: 500px; width: 500px; border: 1px solid black; } […]

  • Simple method and chain operation of jQuery based on JS


    I use this article to explain how to use js to implement a simple method of encapsulating jQuery. In this paper, JS implements several methods of jQuery, and I divide it into eight small goals Implement the $(“. Box1”). Click() method Implement the $(“div”). Click() method Consider three cases of parameters in $() Implementation of […]

  • ROS creation function package


    After entering the command to create a function package, the following situation occurs, and it cannot be created.If there is a boss who knows how to solve the problem, ask [face] monkey2:025. PNG / facemonkey2:025. PNG / facemonkey2:025. PNG [/ face][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url][url]https://www.douban.com/doulis…[/url][url]https://m.douban.com/doulist/…[/url][url]https://book.douban.com/douli…[/url][url]https://movie.douban.com/doul…[/url]

  • The role of JDBC type in mybatis


    background See colleagues using JDBC type in code, I am very confused. knowledge This is for the security of the program. In some special cases, when the passed in parameter name is empty, the program will not have problems. When the name is empty, mybatis does not know what JDBC type to convert to. In […]

  • Ubuntu view and release port 80


    Find occupied ports netstat -tln netstat -tln | grep 80 Netstat – TLN view the usage of all ports, netstat – TLN | grep 80 only view the usage of port 80 Check which process is using the port lsof -i :80 Kill the process that occupies port 80 Kill – 9 process ID