The boss will take you into the world of Android development, mastering these knowledge points, learning Android can also be very easy.

Core analysis content

For how to learn Android, there are mainly three problems to be solved: what to learn, how to learn & how to use .
details as follows:

Below, I will take the above questions to explain in detail my own method of learning Android and Android learning path; ** Finally, combined with the previous content, I will give a comprehensive specific implementation of learning Android recommendations.

Project actual combat

Start speed
Fluency
The practice of Douyin in APK package size resource optimization
Full analysis of Youku's responsive layout technology
Network Optimization
Revealing the Secret of the Performance Optimization Project on Taobao Double Eleven
Analysis of source code dependence of AutoNavi APP full link
Sharing of actual combat experience of completely eliminating OOM
WeChat Android terminal memory optimization practice

theory

In terms of Android application optimization, we mainly optimize from the following 6 aspects:

Optimization of startup speed and execution efficiency
Layout detection and optimization
Memory optimization
Power consumption optimization
Network transmission and data storage optimization
APK size optimization

1. Start-up speed and execution efficiency optimization

Cold start and hot start analysis
This section mainly introduces the startup method, characteristics, application startup process, measuring application startup time, what is the startup time of the application, reducing the time-consuming application startup, and optimizing the experience of the application startup.
APP start black and white screen solution
Solution 1, change the background of the white screen to a picture; Solution 2, make the background of the white screen transparent.
The
16ms principle of APP jam problem analysis and solutions ;
jam processing;
Triple Buffer, since frame loss is inevitable, the Android team has never given up on the optimization of this area, so Triple Buffer (three buffer mechanism) appeared.
StrictMode Detailed StrictMode, Systrace and TraceView for optimization of startup speed and execution efficiency .

2. Layout detection and optimization

Layout level optimization
Every component and layout of the program needs to be initialized, laid out and drawn. If the layout nesting level is too deep, it will cause the loading operation to be more time-consuming, and even more serious, it may cause memory overflow. This section learns to use two tools to check and optimize Layout.
Over-rendering
Since the number of over-rendering can be known through the system settings, the value is read during the test, and the report is completed. Why automate? Because when testing the app systematically, you will find that there are many pages. For example, there are more than 20 pages for the first and second levels of the housekeeper, and the integration package, gray package, formal package, and regression package must be tested once, so it is automated Over-rendering count reading is necessary.

Three, memory optimization

Due to the sandbox mechanism of Android applications, the size of the memory allocated by each application is limited. If the memory is too low, the LMK (Low Memory Killer) mechanism will be triggered, which will cause a crash. If you want to optimize memory, you need to understand how java memory is allocated and recycled. In this regard, you can focus on the following:

Mainly contains

Memory jitter and memory leak
Large memory users, Bitmap memory optimization
Profile memory monitoring tool
Mat large object and leak detection

Fourth, power consumption optimization

If an app is rarely used, but the power consumption of the app is high, then the user will definitely want to uninstall the app directly. So how to reduce the power consumption of your app is a very important thing.

What are the power consumption factors?

(1) Alarm Manager wakeup wakes up too much
(2) Frequent use of local wake locks
(3) Background network usage is too high
(4) Background WiFi scans are too much

Details include

Doze&Standby
Battery Historian
JobScheduler、WorkManager

Five, network transmission and data storage optimization

google serialization tool protobuf
7z ultimate compression

Six, APK size optimization

Let our apk file be as small as possible, remove those unused code and resource files, save downloads and improve efficiency.

APK slimming
WeChat resource confusion principle

to sum up

Finally, the editor wants to say: No matter what direction you choose to develop in the future, it is important to learn Android technology well. After all, for programmers, there are too many knowledge content and technology to learn, if you don’t want to be affected by the environment Elimination is only to constantly improve ourselves. It is always ours to adapt to the environment, not the environment to adapt to us!

Here are dozens of Android interview questions compiled by Tencent, ByteDance, JD, Xiaomi, Toutiao, Ali, Meituan and other companies in 19 years. The technical points are organized into videos and PDFs (in fact, a lot of effort was spent than expected), including knowledge + many details.

Due to limited space, I will show you a small part in the form of pictures.

The detailed arrangement can be seen on GitHub;

Android architecture video + BAT interview topic PDF + study notes

There are a lot of materials for learning Android on the Internet, but if the knowledge learned is not structured, and when you encounter problems, you just taste it and stop studying it in depth, then it is difficult to achieve real technological improvement. I hope that this systematic technical system will provide you with a direction reference.

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