Articles
android

How to do unit testing in the Vue project of the front end grab job series

Regarding unit testing, the most common question should be "Is front-end unit testing necessary?" Through this article, you will understand the necessity of unit testing and how to fully and reliably test the components we wrote in the Vue project . This article was first published on the public account Front-end Reading For more exciting content, please pay attention to the latest news on the official account. The need for unit testing Generally, in our impression, unit testing is the work of

... Marcus
schedule 27 min read
android

Android

Android setContentView Activity Activity getWindow() Window PhoneWindow setContentView( ) frameworks/base/core/java/android/app/Activity.java public class Activity extends ContextThemeWrapper implements LayoutInflater.Factory2, Window.Callback, KeyEvent.Callback, OnCreateContextMenuListener, ComponentCallbacks2, Window.OnWindowDismissedCallback { ...... public void setContentView(@LayoutRes int layoutResID) { getWindow().setContentView(layoutResID); // ActionBar initWindowDecorActionBar(); } ..

... Silas
schedule 11 min read
android

OpenCV combat [2] HOG+SVM realizes pedestrian detection

table of Contents What is HOG? HOG vs SIFT HOG steps HOG's way of detecting pedestrians Opencv implementation The constructor of HOGDescriptor: Pedestrian detection HOG+SVM steps Simplified HOG calculation What is HOG? Histogram of Oriented Gradient (HOG) feature is a feature descriptor used for object detection in computer vision and image processing. It composes features by calculating and counting the histogram of the gradient direction of the local area of the image . Hog feature combined wi

... Kai
schedule 16 min read
android

Inconsistent refresh mechanism under Android View double-buffered drawing

Preface Students who often write custom Views will know that when the View changes, they want to actively refresh the View. There are nothing more than two methods: the main thread calls invalidate(), and the child thread calls postInvalidate(). After calling the above two methods, the system will refresh our View at an appropriate time, that is, call back the onDraw method. With this understanding, we will assume that when we exclude other interfering factors, as long as we don't call the invit

... Bryson
schedule 8 min read
android

Please know about Kotlin inline class

In the recent development work, I accidentally discovered an inline bug officially recognized by Kotlin. In the process of understanding the cause of this bug, I uphold the determination to break the casserole to the end, and even learn a wave of jvm bytecode. Gained a lot, so I started to write this article and share this learning process with everyone. This article is very long, but after reading it patiently, I am sure everyone will find it very worthwhile. I heard that the inline class is ve

... Bentley
schedule 18 min read
coder_life

Design of multifunctional electronic perpetual calendar based on 51 single chip microcomputer (LCD12864+DS1302+DS18B20)

With the development of electronic technology, human beings continue to research and continuously set new records. The perpetual calendar is no longer limited to appearing in book form. Perpetual calendars in the form of computer software or electronic products are called electronic perpetual calendars. Compared with the traditional perpetual calendar in the form of a book, the electronic perpetual calendar has been more and more widely used, and it has become a fashion to use an electronic cloc

... Olivia
schedule 47 min read
coder_life

Python thread mutex lock-Python zero-based introductory tutorial

table of Contents I. Introduction 2. Python threads share global variables Three. Python thread mutex lock 1. Create a mutex 2. Lock resources / unlock resources Four. Python thread deadlock V. Key summary 6. Guess you like it I. Introduction In the previous article, Python thread creation and parameter transfer , we introduced some simple function usage and thread parameter transfer about Python threads. Using multiple threads can perform multiple tasks at the same time and improve development

... Miguel
schedule 11 min read
coder_life

Algorithm diagram reading notes

Big O notation When discussing running time in Big O notation, log refers to log2. Big O notation is a special notation that points out how fast the algorithm is. For example, suppose the list contains n elements. Simple search needs to check every element, so it needs to perform n operations. Using Big O notation, this running time is O(n). What about seconds? No-Big O notation does not refer to speed in seconds. Big O notation allows you to compare operands, and it points out how fast the algo

... Alan
schedule 29 min read
coder_life

set

  Long before Java 2, Java provided ad hoc classes. For example: Dictionary, Vector, Stack, and Properties classes are used to store and manipulate object groups. Although these classes are very useful, they lack a core, unified theme. For this reason, the way of using the Vector class is very different from the way of using the Properties class. The collection framework is designed to meet the following goals. The framework must be high-performance. The implementation of basic collections

... Daisy
schedule 13 min read
coder_life

Teach you how to use Hongmeng OS to realize smart home LOT cloud project

Teach you how to use Hongmeng OS to realize smart home LOT cloud project I. Introduction Today, I use Hongmeng OS to make a smart home project on the cloud by LOT. The scenario we want to achieve is this: Cloud WEB has a control interface that can control the lights and fans in the room, and display the temperature, humidity, and light intensity in the room in real time. 2. Case ideas Let's talk about the general idea first, which can be divided into two parts: first configure the cloud server,

... Elijah
schedule 18 min read
dev_tools

2021 latest Spring Security knowledge combing

1. Introduction to Spring Security Framework Spring is a very popular and successful Java application development framework, and Spring Security is a member of the Spring family. Based on the Spring framework, Spring Security provides a complete solution for web application security. As you may know about security, the two main areas are "authentication" and "authorization" (or access control). Generally speaking, the security of web applications includes user authentication (Authentication) and

... Adeline
schedule 23 min read
dev_tools

Git study notes

A good scenario-based Git best practice manual (multilingual): github.com/k88hudson/g... Git version control and storage model What is Git and why use Git Imagine a scenario: you have written a file whose version is 1.0. Now you need to modify and optimize the content. You are afraid of losing the original file, so you copy the 1.0 version of the file and make changes on this copy. The two files can't cause too much trouble. However, in actual study and work, we often encounter multiple files i

... Angel
schedule 36 min read
dev_tools

Efficient development: full analysis of Spring's various annotations

table of Contents I. Introduction 2. Common annotations: @Autowired annotation 2.1 Introduction: Do not use any annotations (comparison with the annotations used later) 2.2 @Autowired annotation 2.2.1 @Autowired labels class member variables 2.2.2 @Autowired annotates the setter method (set value injection) 2.2.3 @Autowired annotates the constructor (construction injection) 3. Common annotations: @Component annotation 3.1 @Component annotation: Student does not refer to class member variables 3.

... Leonardo
schedule 17 min read
dev_tools

quick-cocos2d-x learning series 13 touch

quick-cocos2d-x learning series 13 touch   Nowadays, smartphones are basically touch screens, except for keyboard enthusiasts. We need to control the entire game logic through this small touch screen, and we need to control this big palm area in detail.   1. Single touch test Create sprite function function createTouchableSprite (p)     local sprite = display .newScale9Sprite(p.image)     sprite:setContentSize(p.size)       local cs = s

... Makayla
schedule 18 min read
dev_tools

Detailed explanation of the services in the cache architecture! Implementation of the second-level cache service in SpringBoot

Create a cache service Create a cache service interface project Create the myshop-service-redis-api project, which is only responsible for defining the interface Create the pom.xml of the project : <?xml version="1.0" encoding="UTF-8"?> < project xmlns = "http://maven.apache.org/POM/4.0.0" xmlns:xsi = "http://www.w3 .org/2001/XMLSchema-instance" xsi:schemaLocation = "http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" > < modelVersion > 4.0.0 </ m

... Alan
schedule 7 min read
programming

One article to solve the front-end interview ----HTML and CSS (the most detailed summary of the two swordsmen )

Write in front Hello, everyone. I m Kerwin and R. I m doing an internship at Tencent. I have received help from many people along the way. I have also read articles from various great gods. Now I will slowly summarize and open up all my notes. I hope to be able to Help more people and be able to make progress with you. If there is any problem with the article, I hope to raise it in time so as not to mislead more people. I like concise answers. I don't like long-form answers. I will try my best t

... Henry
schedule 20 min read
programming

Asynchronous application of ES6(13)Generator

basic concepts Coroutine: multiple threads cooperate with each other to complete asynchronous tasks A coroutine is a bit like a function, but also a bit like a thread. Its running process is roughly as follows: In the first step, the coroutine A starts to execute. In the second step, the execution of coroutine A is halfway through, enters a pause, and the execution right is transferred to coroutine B. In the third step, (after a period of time) Coroutine B returns the execution right. In the fou

... Matthew
schedule 14 min read
programming

Node.js knowledge system (7)-Promise of asynchronous programming

This is the text I was involved in more challenging twenty-seven days, the event details see: more text challenge What is Promise Promise is a solution for asynchronous programming! Results that are not available in the current event loop, but future event loops will give you results Is a state machine pengding resolved reejectd Look at the state flow from the code Transfer test from pending to resolve ( function () { const res = new Promise ( ( resolve, reject ) => { setTimeout ( () => {

... Natalie
schedule 10 min read
programming

Three ways to merge two ordered arrays Java

This article is participating in the "Java Topics month - Java brush title punch" to view details about active links Title description This is 88 on LeetCode. Combine two ordered arrays . Tag: "Dual pointer", "Sort" Given two ordered integer arrays nums1 and nums2, please merge nums2 into nums1 to make nums1 an ordered array. Initialize the number of elements of nums1 and nums2 to m and n respectively. You can assume that the space size of nums1 is equal to m + n, so that it has enough space to

... Harrison
schedule 6 min read
programming

In-depth analysis: Are Redis distributed locks safe? After reading this article, I thoroughly understand it!

Wechat search followed the "Water Drop and Silver Bullet" public account to get high-quality technical dry goods in the first place. 7 years of senior back-end research and development, showing you a different technical perspective. Hi everyone, my name is Kaito. In this article, I want to talk to you about the "security" of Redis distributed locks. Many articles on the topic of Redis distributed locks have been written badly. Why should I write this article? Because I found that 99% of the art

... Quinn
schedule 43 min read
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