Articles
android

3.11 [HarmonyOS Hongmeng Development] Component TimePicker

3.11 [HarmonyOS Hongmeng Development] Component TimePicker Author: Han Ru Company: Program Cafe (Beijing) Technology Co., Ltd. Hongmeng Bus Columnist TimePicker is mainly for users to choose the time. 1. Supported XML attributes The common XML attributes of TimePicker are inherited from: StackLayout TimePicker's own XML attributes are shown in the following table: Attribute nameChinese descriptionValueValue descriptionUse Casesam_pm_orderMorning and afternoon order0Indicates that the am/pm colum

... Isaac
schedule 6 min read
android

Knowledge points of Android basic interview questions in 2021

I. Introduction Although it's already May, it's not the golden season, but no matter what month, there should be programmers looking for work. Even if it s not for job hunting, you can consolidate your knowledge points. After all, I clicked on this article . Okay, not much to say, let's turn on the question mode. Second, brush questions 1. What is the life cycle of Activity and Fragment (without explanation, attach a picture) 2. The life cycle problem of switching Activity between horizontal and

... Camden
schedule 27 min read
android

Ali P8 boss will take you to learn Java lock in 3 minutes

This article is transferred from: Le byte article Main explanation: Java lock For more Java related knowledge, you can follow the public account "Le Byte" Send: 999 1 Introduction Large concurrent operations of the database should consider the performance issues of deadlocks and locks. I see that most of the language on the Internet is unclear (especially update locks), so here is a concise explanation, for the convenience of the following description, here T1 represents a database execution req

... Isaac
schedule 20 min read
android

Variables in Bash script tutorial

table of Contents Introduction Create variable Read variable Delete variable Output variables, export command Special variable The default value of the variable declare command readonly command let command Bash variables are divided into environment variables and custom variables. Introduction Environment variables are the variables that come with the Bash environment. They have been defined when entering the Shell and can be used directly. They are usually defined by the system, and they can al

... Bryce
schedule 15 min read
android

Vue uses the el-table back-end filtering function in elementui to explain

Problem Description For the background management system, the more common function is to add, delete, modify and check. For "check", it is more common to filter data to view. Hungry? The ui comes with a filtering function. However, the example given in the official document is "front-end filtering", which means that hard-coded data is filtered out by the front-end for presentation. The official renderings are as follows: However, in actual development, the data is dynamically retrieved from the

... Calvin
schedule 8 min read
coder_life

MQ RabbitMQ 2021

MQ MQ - - - - - A BCD E C A A A A MQ A MQ MQ MQ MQ A MQ A BCD 3ms BCD 300ms 450ms 200ms 3 + 300 + 450 + 200 = 953ms 1s MQ A 3 MQ 5ms A 3 + 5 = 8ms RabbitMQ A BCD BD C 10 RabbitMQ MQ ActiveMQ ActiveMQ ActiveMQ RabbitMQ RabbitMQ case RabbitMQ RabbitMQ bug RabbitMQ RabbitMQ erlang erlang RocketMQ RocketMQ Java Kafka Kafka MQ Kafka Kafka Spark Streaming Storm Flink MQ Kafka ActiveMQ RabbitMQ RocketMQ ActiveMQRabbitMQRocketMQKafkaZeroMQ RabbitMQ 2.6w/s 11.6w/s17.3w/s29w/s JavaErlangJavaScala/JavaC A

... Alyssa
schedule 16 min read
coder_life

Facebook's C++ 11 component library Folly Futures

English original: code.facebook.com/posts/16619... www.oschina.net/translate/f... www.lupaworld.com/article-254... Futures are a model for expressing asynchronous computing in a natural and composable way. This blog post introduces a C++11 futures implementation we use in Facebook : Folly Futures . Why use asynchronous? Imagine a scenario where service A is interacting with service B. If A is locked to B before it can continue to perform other operations after replying, then A is synchronized. A

... Hannah
schedule 14 min read
coder_life

[Image segmentation] Image segmentation matlab source code based on ant colony optimization fuzzy clustering

Ant Colony Algorithm Introduction Ant colony optimization (ACO), also known as ant algorithm, is a probabilistic algorithm used to find optimized paths in the graph. It was proposed by Marco Dorigo in his doctoral dissertation in 1992, and was inspired by the behavior of ants finding paths in the process of searching for food. Ant colony algorithm is a simulated evolutionary algorithm. Preliminary research shows that the algorithm has many excellent properties. Aiming at the problem of PID contr

... Lily
schedule 16 min read
coder_life

LCA

ACM template DFS + ST online algorithm Reference topic link: POJ 1330 Nearest Common Ancestors const int MAXN = 10010 ; int rmq[ 2 * MAXN]; // rmq array is the depth sequence corresponding to Euler sequence struct ST { int mm[ 2 * MAXN]; int dp[ 2 * MAXN][ 20 ]; // the subscript corresponding to the minimum value void init ( int n) { mm[ 0 ] = -1 ; for ( int i = 1 ; i <= n; i++) { mm[i] = ((i & (i- 1 )) == 0 )? mm[i- 1 ] + 1 : mm[i- 1 ]; dp[i][ 0 ] = i; } for ( int j = 1 ; j <= mm[n];

... Cooper
schedule 9 min read
coder_life

[LeetCode] 28. Implement strstr() (KMP super detailed explanation, sunday solution and other five methods, java implementation)

topic link analysis Overview This question is to find the needle string in the haystack string. Three solutions are given below, all of which are based on sliding windows. The simplest solution is to compare substrings one by one. The sliding window of length L is gradually moved along the haystack string, and the substring in the window is compared with the needle string. The time complexity is O((N-L)L ) Show the above method can be optimized. Although the double pointer method is also linear

... Richard
schedule 32 min read
dev_tools

This article takes you in-depth understanding of the IOC startup principle

1. IOC overview 1.1 What is it? Two concepts: inversion of control, dependency injection **Look at the traditional way of working: **Based on the single responsibility principle of an object, an object rarely completes its own work without relying on other objects, so at this time there will be dependencies between objects. And in our development, when we need any object, we will create what object, at this time the control of object creation is in our own hands. When too many objects are create

... Levi
schedule 17 min read
dev_tools

[Vite principle] connect source code interpretation

The original link of the author's blog: www.yingpengsha.com/vite-yuan-l... Overview connect is an extensible HTTP service framework of NodeJS, which can use middleware to extend functions Both vite and webpack-dev-middleware use connect to build development servers, and Express 's middleware model is also borrowed from connect. When I read the source code of Vite, I found that Vite uses connect as the core to build a development server, so I have this article. The article is divided into two pa

... Landon
schedule 13 min read
dev_tools

Microcomputer Principle-Design of Extended Memory

table of Contents [1] The hierarchical structure of the memory [2] Classification of memory [3] SRAM 1. Basic principles: 2. Structure: 3. Interpretation of chip parameters and pins: 4. Connection between CPU and SRAM [4] DRAM 1. Basic principles: 2. Structure 3. Interpretation of chip pins: [5] Memory system design [6] Memory expansion design (emphasis) 1. Bit extension (bit parallel method) 2. Byte extension (address concatenation method) 3. Byte and bit extension [7] Chip selection signal gen

... Benjamin
schedule 14 min read
dev_tools

It's really dry! This 40,000-character super-long dry goods thoroughly analyzes the "six principles of design patterns"! It is recommended to read repeatedly.

Today I am finishing and updating an article on the six principles of design patterns, mainly about learning paths. I will look for opportunities to update interview articles in the future. So, pay attention, don t get lost, you can see my updates first! One | Super Dry Goods 1. Single responsibility principle 1. Definition First, let's take a look at the definition of a single responsibility. The single responsibility principle, the full name is Single Responsibility Principle, or SRP for shor

... Hudson
schedule 72 min read
dev_tools

JimuReport building block report version 1.3.3 released, a visual report tool

Project Introduction Building block report is a free visual web report tool, drag and drop online report design like building blocks! The function covers, data report, print design, chart report, large screen design, etc.! Adhering to the "simple, easy-to-use, professional" product concept, it greatly reduces the difficulty of report development, shortens the development cycle, saves costs, and solves various report problems. The key point is that this software is completely free! ! ! Current ve

... Evan
schedule 8 min read
programming

Analysis of Servlet

(1) Basic overview of Setvlet (1) What is Servlet? Servlet (Server Applet) is the abbreviation of JavaServlet, called small service program or service connector. The server-side program written in Java has the characteristics of being independent of platform and protocol. The main function is to browse and generate data interactively, and generate dynamic Web content is In JavaWeb, we will be exposed to three major components ( Servlet , Filter , Listener ) Servlet is called by the server to pro

... Marcus
schedule 20 min read
programming

[ID card recognition] ID card number recognition based on matlab GUI [including Matlab source code 014]

1. Introduction ID card number recognition based on matlab GUI Second, the source code function varargout = homework2(varargin) % HOMEWORK2 M-file for homework2.fig % HOMEWORK2, by itself, creates a new HOMEWORK2 or raises the existing % singleton*. % % H = HOMEWORK2 returns the handle to a new HOMEWORK2 or the handle to % the existing singleton*. % % HOMEWORK2( 'CALLBACK' ,hObject,eventData,handles,...) calls the local % function named CALLBACK in HOMEWORK2.M with the given input arguments. % %

... Ruby
schedule 9 min read
programming

What to do if the dependent service fails? Millions of projects are going to be roadshow demo tomorrow

This is the 6th day that I participated in the Wenwen Challenge. For details of the event, please view: Wenwen Challenge What to do if the dependent service fails? Millions of projects are going to be roadshow demo tomorrow Scenes Sometimes entrepreneurs will develop and produce some projects, such as some apps, and go to the entrepreneurial park to show them. But things were unsatisfactory, some services that the App relied on failed, and the first screen (the homepage couldn't be logged in for

... Bentley
schedule 12 min read
programming

The difference between unittest and pytest

1. unittest # MyFunction.py DEF the Add ( A, B ): return A + B duplicated code 1.1 unittest unit test # Unit test.py """ 1. Unit testing framework: automatic verification results python:unittest or pytest, Java: Junit, TestNG How to write use cases: Must start with test Find use cases to parameterize """ import unittest import myFunction import HTMLTestRunner import HTMLTestRunnerNew # rich version of test report import parameterized # parameterized class TestAdd ( unittest.TestCase ): '''Test a

... Hannah
schedule 11 min read
programming

[Fruit recognition] Fruit size recognition based on matlab GUI morphology [Contains Matlab source code 920]

1. Introduction Mathematical morphology operations can be divided into binary morphology and gray morphology, and gray morphology is extended from binary morphology. Mathematical morphology has two basic operations, namely corrosion and expansion, and the combination of corrosion and expansion forms an opening operation and a closing operation. The open operation is to first corrode and then expand, and the closed operation is to first expand and then corrode. 1 Binary Morphology Roughly speakin

... Summer
schedule 12 min read
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