Articles
android

Android Studio Arctic Fox (2020.3.1) Beta released

Android Studio Arctic Fox startup screen Author/ Paris Hsu, Product & Design, Android Note: As we announced late last year that we have changed the version numbering scheme to match the number IntelliJ IDE Android Studio is based, namely 2020.3, combined with our own patch number, as well as a code name easy to remember and use. We will arrange the code names in alphabetical order. The first one is Arctic Fox, which is now in Beta; the next code name is Bumblebee, which is still in the Cana

... Hailey
schedule 13 min read
android

Tencent Location Service GPS Track Playback-Android

Preface When we use the map for development, it is a very common method to check the accuracy of the navigation by using the recorded trajectory to replay the trajectory. And the previous article has already finished the recording of the GPS trajectory file when the map is used. Use Tencent Navigation SDK for track playback to share Preliminary preparation Tencent Navigation SDK relies on Tencent Map SDK and Tencent Positioning SDK. You need to go to the official website console of lbs.qq.com to

... Hailey
schedule 15 min read
android

[Data structure and algorithm] Introduction to graph actual combat

1 Overview 1.1 The composition of the graph The graph is composed of two sets: the point set V, the edge set E, and the binary definition is G = (V, E). 1.2 Directed and undirected graphs The graph is divided into: directed graph, undirected graph. Undirected graph: Each edge is bidirectional, and (x, y) and (y, x) represent the same result. Directed graph: Each edge is unidirectional, and <x, y> and <y, x> indicate different results. 1.3 In-degree and out-degree Degrees are divided

... Emmett
schedule 26 min read
android

Code refactoring

Hello everyone, this is the catalog of my speech today, divided into three programming languages: Java, JavaScript, and ABAP. Java JAD javap Java Decompiler Source Monitor Visual VM Refactor Menu in Eclipse ABAP Code inspector Refactor feature in AIE Code coverage JavaScript ESLint for Fiori Apps Check Jenkins build log JSlint for Sublime Text 2 Code check in WebIDE Profile in Chrome Is it correct to introduce a boolean parameter in the method to control the behavior of the method? See what it

... Molly
schedule 9 min read
android

In-depth understanding of Java dynamic proxy mechanism

Java has two proxy methods, one is static proxy and the other is dynamic proxy. For static proxy, in fact, it is through dependency injection to encapsulate the object and prevent the outside from knowing the details of the implementation. Many APIs are encapsulated in this form. Agency mode structure diagram (picture from "Dahua Design Mode") Let's take a look at the conceptual explanation of the two: Static proxy Static proxy class: created by the programmer or generated by a third-party tool,

... Eli
schedule 17 min read
coder_life

LeetCode.122 The Best Time to Buy and Sell Stocks II

This is the 30th day I participated in the Wenwen Challenge. For details of the event, please see: Wenwen Challenge Title description: Original title address Given an array prices ,among them prices[i] Is a given stock i Price per day. Design an algorithm to calculate the maximum profit you can get. You can complete as many transactions as possible (buying and selling a stock multiple times). note: You cannot participate in multiple transactions at the same time (you must sell the previous

... Cameron
schedule 5 min read
coder_life

Common design patterns of game programming

Author: Old Nine Technology Social: Zhihu Public number: Laojiu School (the newcomers have surprises) Special statement: originality is not easy, no reprinting or plagiarism is allowed without authorization, if you need to reprint, please contact the author for authorization Preface When it comes to design patterns, you might think of Java as a programming language. In fact, playing the design pattern C++ is the ancestor. Without mastering design patterns, it is impossible to write very complex

... Carter
schedule 25 min read
coder_life

OC SEL (@selector) principle and use summary

Article source: blog.csdn.net/fengsh998/a... Pointer to SEL class member method It can be understood that @selector() is the number of the class method. Its behavior is basically equivalent to the function pointer in the C language, but in the C language, the function name can be directly assigned to a function pointer, while the Object-C class cannot Directly apply the function pointer, so that only a @selector syntax can be used to fetch it. Its result is a SEL type. This type is essentially t

... Asher
schedule 9 min read
coder_life

springboot2 integrates vue to develop online music website [source code open source]

This weekend, Meng Ge organized an online music website based on springboot+vue for everyone.   The project is very nice in terms of function and interface, and the source code is free and open source for everyone.   Official account, reply: boot music   1. System installation   a. Download the resources recorded in the database Backstage reply: song picture Download the songs and pictures that the website relies on, and put the files in the data folder directly under the mus

... Abraham
schedule 15 min read
coder_life

Leetcode Total Collection

Preface Just as [offer] to prove safety lumped said, to prove safety and offer LeetCode topic, often a test of our understanding of algorithms and data structures therein. This article summarizes the 100 questions and links to Leetcode questions that have a relatively high interview rate. There are many topics that are the same as Jianzhi offer. If so, I will explain in the topic. Topic index My index structure is: Data structure 1: |____ Mission Objective-Topic 1 |____ Mission Objective-Topic 2

... Calvin
schedule 6 min read
dev_tools

"Unity development can also be linked to hardware"-come and take a look (serial communication)

One, C# serial port introduction and simple serial port communication program design and implementation Simple serial communication tool, based on C# application WinFrom Serial port introduction Serial interface is abbreviated as serial port, also called serial communication interface or serial communication interface (usually referred to as COM interface), which is an extended interface using serial communication. (As for further details, Baidu yourself) Serial port application It is widely use

... Molly
schedule 11 min read
dev_tools

"You can also enter the big factory" multi-threaded series-volatile, happens-before, three-level cache

This is the 5th day that I participated in the change of text challenge. For details of the event, please see: Change of text challenge Author: JavaGieGie WeChat public account: Java development zero to one Preface The holidays are over and I started to work, and it was another day full of frustration. Fortunately, I was accompanied by Hua Gie's articles, otherwise I would be lonely to death (smelly shameless). Multithreading has introduced a lot of knowledge about three multithreading. Those wh

... Greyson
schedule 14 min read
dev_tools

R language portfolio optimization solver: conditional constraint optimization, nonlinear programming solution

Original link: tecdat.cn/?p=22853 Original source: Tuoduan Data Tribe Official Account This article will introduce the different solvers available for portfolio optimization in R. General solver A general solver can handle any nonlinear optimization problem, but the cost may be slow convergence. Default package The package stats (the basic R package installed by default) provides several general optimization programs. optimize(). Used for one-dimensional unconstrained function optimization in th

... Liam
schedule 10 min read
dev_tools

Java operation FTP and SFTP upload/download files

version Linux is CentOS7.x Java is jdk8 FTP Prepare something Ready to ask for 1. Install ftp (vsftpd) on the corresponding linux article to install vsftpd 2. Linux create ftp user useradd account passwd account# (Enter) Set the login password for the user-enter it twice, pay attention to the password will not be displayed, enter the correct entry and enter userdel account - delete tail /etc/passwd - view all accounts Copy code 2. Create a project 3. Import the corresponding dependencies! ! ! &l

... Calvin
schedule 10 min read
dev_tools

13. CSS layout design summary (Ultimate Edition)

1. Two-column layout (seven schemes) The two-column layout is generally specified width and adaptive layout, the left column of the two columns is the determined width, and the right column is a layout effect that automatically fills all the remaining space; Left column adaptive, right column fixed width (scheme summary) 1. Float + margin property realization; 2. Realization of float + overflow property; 3. Realization of table related values of display attribute; 4. Use absolute positioning to

... Greyson
schedule 25 min read
programming

StampedLock, the artifact to solve thread hunger, deserves it!

Preface The introduction of StampedLock in JDK 1.8 can be understood as an enhancement of ReentrantReadWriteLock in some aspects. A new mode called Optimistic Reading is added on the basis of the original read-write lock. This mode does not lock, so it will not block threads, and will have higher throughput and higher performance. Concurrent programming practical notes are also worth looking at. Let s take a look at what StampedLock brings to us... With ReentrantReadWriteLock, why introduce Stam

... Eli
schedule 17 min read
programming

Algorithmic problem review (quick sorting, linked list, dichotomy, hash, double pointer)

table of Contents 1. Quick sort review 2. Part of the linked list review 203. Remove linked list elements 707. Design Linked List 206. Reverse Linked List 142. Circular Linked List II 3. Dichotomy review 4. Hash method review 5. Double pointer review **15. Sum of Three Numbers** **18. Sum of Four Numbers** **27. Remove elements** **344. Reverse string**, simple, double pointer moves closer to the middle from both sides, and swap at any time **Sword refers to Offer 05. Replace spaces** **151. Re

... Blake
schedule 16 min read
programming

The implementation source code of replying to social media information in SAP CRM call center

We know that in the social media integration solution of the SAP CRM call center, if a twitter account is configured in the system, then those tweets @ the account on the twitter website will automatically be caught in the SAP CRM call center for delivery Agent processing. The test tweet of @AndrewPang6 in the above picture is as follows after grabbing the SAP CRM call center. The agent of the call center can reply by clicking the Reply button in the CRM system. Customers can see the reply by op

... Jayce
schedule 8 min read
programming

Seven, file operation function

Seven, file operation function The file operation function completes the functions of file input, modification, output, validity check, deletion, and determination of file length. Before accessing the data in the file, you need to open the file first. After the file is used up, you need to close the file. There are two ways to open a file: Line Mode and Stream Mode. In line mode, when reading data, one line at a time is written until it reaches the carriage return (CR) line feed (LF) character o

... Aaron
schedule 22 min read
programming

How long does it take to make an official website

Author : Xiaotudou Blog Garden: www.cnblogs.com/HouJiao/Nuggets : juejin.cn/user/243617... 1 Introduction I'm currently making an official website, homepageMenu BarHaveSix, Corresponding to six large modules, the display form of each module is roughly as follows: 1.1 Pure picture display A main image fills the browser horizontally: 1.2 Table display 1.3 Picture + text left and right two column layout display The first two-column layout: The second two-column layout: 1.4 Picture + text two-line

... Logan
schedule 33 min read
9 10 11 12 13 14 15 16 17 18 19 20