Android App Development guide for beginners.

适用于初学者的Android应用开发指南。

Why you should learn android development.

为什么要学习android开发。

• If you want a well-paying job, then you should go for the Android app development. According to the glassdoor website: the average salary for an Android developer is approximately 6 lakh per annum in India and the average salary for an Android developer is $ 96,000 per annum in the United States.如果您想要一份高薪工作，那么您应该去进行Android应用程序开发。 根据glassdoor网站的数据：在印度，Android开发人员的平均年薪约为60万美元，Android开发人员的平均年薪为96,000美元。
• If you are an aspiring entrepreneur, you must also learn to develop Android applications. Many startup ideas need an Android app. Consider if you want to build a startup that helps people rent power banks for mobile charging, then it would be great if you had a dedicated Android app for that.如果您是一位有抱负的企业家，那么您还必须学习开发Android应用程序。 许多启动创意都需要一个Android应用。 考虑一下，如果您想建立一个可以帮助人们租用移动电源进行移动充电的初创公司，那么如果您有一个专门的Android应用程序就可以了。
• The Android mobile operating system has a good reach and is available in 70% to 75% of all smartphones. There is a huge supply of jobs and the demand for Android developers will increase as apps for smartwatches and smart TVs are increasing.Android移动操作系统覆盖面很广，在所有智能手机中有70％至75％可用。 随着大量用于智能手表和智能电视的应用程序的出现，大量的工作机会和对Android开发人员的需求将会增加。

Android is an open source software package that is based on the Linux operating system. There have been several versions of Android available with code names and API level.

Android是基于Linux操作系统的开源软件包。 已有多个版本的Android，其中包含代码名称和API级别。

There are mainly two types of applications that can be built for Android platforms.

可以为Android平台构建的应用程序主要有两种。

• Native applications: They are built in a specific language that is compatible with the Android operating system. These Android specific languages include Java and Kotlin.本机应用程序：它们以与Android操作系统兼容的特定语言构建。 这些特定于Android的语言包括Java和Kotlin。
• Hybrid applications — They are built with coding languages used for creating websites which includes HTML, CSS and Javascript.混合应用程序-它们使用用于创建网站的编码语言构建，包括HTML，CSS和Javascript。
• As a beginner, I suggest that first you practice creating native applications.作为初学者，我建议您首先练习创建本机应用程序。
• There are several advantages to building native applications as a beginner.作为初学者构建本机应用程序有许多优点。
• A native application integrates very well with the device hardware that includes GPS, camera and others.本机应用程序与包括GPS，照相机和其他设备的设备硬件很好地集成在一起。

Now what programming language should you choose to develop native Android apps? You can choose any language between Java and Kotlin.

现在，您应该选择哪种编程语言来开发本机Android应用程序？ 您可以在Java和Kotlin之间选择任何语言。

As a beginner, learning Java will be easy, and there are several online sources available for learning Java.

作为一个初学者，学习Java很容易，并且有许多在线资源可供学习Java。

• Tutorial for learning Java — Free on Youtube

  学习Java的教程—在YouTube上免费

• Tutorial for learning Kotlin — Free on Youtube

  学习Kotlin的教程—在YouTube上免费

How much Java, Kotlin knowledge do you need to begin android development?

您需要多少Java，Kotlin知识来开始进行android开发？

There is a common misconception among students trying to learn Android development that they need to become Java or Kotlin experts.

在试图学习Android开发的学生中，普遍存在一种误解，即他们需要成为Java或Kotlin专家。

You don’t have to be a Java or Kotlin expert to learn Android.

您无需成为Java或Kotlin专家即可学习Android。

Here is a list of all the concepts in java language you will need for developing applications.

这是开发应用程序所需的所有Java语言概念的列表。

• How to declare variables. Familiarity with operators, expressions, final keyword, Java string class is also required.如何声明变量。 还需要熟悉运算符，表达式，final关键字，Java字符串类。
• Knowledge about branching and switch statements is must. You will need to know how to declare loops. For example, for and while loop.必须具有有关分支和switch语句的知识。 您将需要知道如何声明循环。 例如，for和while循环。
• How to declare classes, define methods, objects and this keyword will definitely help.如何声明类，定义方法，对象以及此关键字肯定会有所帮助。
• Android application development is based on the concept of OOPs, so you should know all the concepts of OOPs like inheritance, polymorphism. File I/O Basics is required.Android应用程序开发基于OOP的概念，因此您应该了解所有OOP的概念，例如继承，多态性。 需要文件I / O基础。
• If you know all these concepts, you can start with Android development.如果您了解所有这些概念，则可以开始进行Android开发。
• There will be some concepts in Java that you don’t know. If you come across any of these concepts, try learning it right then with a simple Google search.Java中会有一些您不知道的概念。 如果您遇到任何这些概念，请尝试通过简单的Google搜索立即学习。

Resources for learning basics of android app development. I am mentioning some free online learning resources. This is the best resource one can get for free.

用于学习android应用开发基础知识的资源。 我提到的是一些免费的在线学习资源。 这是一个免费的最佳资源。

Android Basics: User Interface — This course consists of beginner-friendly concepts and will teach you the basics of the Android user interface.

Android基础：用户界面 —本课程包含对初学者友好的概念，并将教您Android用户界面的基础。

Android Basics: User Input — In this course, you will create an interactive coffee ordering application. This course will teach how to practically implement OOPs concepts in applications.

Android基础知识：用户输入 -在本课程中，您将创建一个交互式咖啡订购应用程序。 本课程将教授如何在应用程序中实际实现OOP概念。

Android Basics: Multiscreen Apps — In this course you will learn about intents and activities, practically implement loops to display data to users, adding images, playing audio in your app.

Android基础知识：多屏应用 —在本课程中，您将学习意图和活动，实际上将实现循环以向用户显示数据，添加图像，在应用程序中播放音频。

Android Basics: Networking — In this course, you will discover how to use a web API in your Android application, HTTP Networks, and how to use the thread to do time consuming background work, AsyncTask overview.

Android基础知识：网络 —在本课程中，您将发现如何在Android应用程序HTTP网络中使用Web API，以及如何使用线程来完成耗时的后台工作(AsyncTask概述)。

Android Basics: Data Storage — In this course you will discover about the SQLite database in your application, the configuration of the contract class, etc.

Android基础知识：数据存储 —在本课程中，您将发现有关应用程序中SQLite数据库，协定类的配置等信息。

• Take a look at Firebase — it will make Android app development easy.

  看一下Firebase ，它将使Android应用程序开发变得容易。

• With Firebase you can create applications quickly and easily.使用Firebase，您可以快速轻松地创建应用程序。
• After doing all these courses, you will have strong basic knowledge about Android.完成所有这些课程之后，您将具有有关Android的丰富基础知识。
• Now you need to build some projects on your own to see how much you have learned.现在，您需要自己构建一些项目，以了解您学到了多少。

Android Development Projects Ideas.

Android开发项目构想。

Todo List Application

待办事项清单申请

Try to built a todo list application having these features:

尝试构建具有以下功能的待办事项列表应用程序：

• Create a new task list to manage different tasks.创建一个新的任务列表来管理不同的任务。
• Add / edit / delete an item to our Everything list.添加/编辑/删除项目到我们的所有列表。
• Each task can have detailed note options.每个任务可以有详细的注释选项。
• Implement the search option for All.实施全部搜索选项。
• Sort your to-dos and tag them by category.对您的待办事项进行排序，并按类别对其进行标记。

Tinder Clone

火种克隆

Try to create a tinder clone through this app, you will learn about how to create a difficult user interface and how to access Firebase database, Firebase authentication and Firebase storage. It should include these features:

尝试通过此应用程序创建火种克隆，您将了解如何创建困难的用户界面以及如何访问Firebase数据库，Firebase身份验证和Firebase存储。 它应包括以下功能：

• Create an account with name, age, gender and email authentication.创建一个具有名称，年龄，性别和电子邮件身份验证的帐户。
• Sign in to the account.登录到该帐户。
• View user of opposite sex only.仅查看异性用户。
• Add swipe features for every opposite sex user you like.为您喜欢的每个异性用户添加滑动功能。
• Edit your profile and you can add a profile photo.编辑您的个人资料，您可以添加个人资料照片。
• Able to match two users.能够匹配两个用户。
• Once two users match, they should be able to chat with each other.一旦两个用户匹配，他们就应该能够彼此聊天。

Try to build some more applications with what you have learned.

尝试利用所学的知识来构建更多的应用程序。

• Make some applications about using the rest API. As an Android developer, you should always know how to beautifully display json data in your Android app.编写一些有关使用其余API的应用程序。 作为Android开发人员，您应该始终知道如何在Android应用中精美显示JSON数据。

Put your code for all your projects online on github.

将所有项目的代码放在github上在线。

If you get stuck at any point while creating a project always take a look at two great resources.

如果您在创建项目时遇到任何困难，请始终看一下两个有用的资源。

• Stackoverflow: It is likely that all your errors are already fixed here.

  Stackoverflow：您的所有错误很可能已在此处修复。

• Android Documentation: To add any new features to your Android app, you should check its official documentation.

  Android文档：要向您的Android应用添加任何新功能，您应该查看其官方文档。

If you followed all the steps mentioned above, you have become an Android developer and now you can apply for internships at the company you want.

如果您按照上述所有步骤操作，则说明您已经成为Android开发人员，现在可以在所需的公司申请实习机会。

Prepare your resume and cv and discuss all your projects. You will now get an internship in a dream company.

准备简历和简历，并讨论所有项目。 现在，您将在一家梦想公司实习。

Further reading:

进一步阅读：