All you need to know about Android Application development

By Saraschandraa M Android Comments Off

Introduction

Learning how to develop Android Applications seems like a herculean task; however, it can surely open up a vast range of opportunities for you in terms of career development. You could develop the next top application that transforms our ways of work or how we interact. You might create a tool that will help you enhance the way you work and develop an efficient workflow. Or maybe you will just learn a new skill that will get you an amazing job!

In any case, learning Android application development is not as hard as you think it is, as long as you are aware of the purpose of all the different moving parts, and have a development plan to provide you guidance through the development process. Today, we will tell you all you need to know about android application development.

Download the tools that are required for Android Application development

At first, you must ensure that you have an efficient development environment so that your system can support all your goals for android application development. You’re going to require Android Studio and Android SDK. Luckily, they’re both assembled in one download so you can find them easily.

Android Studio is just an IDE; Integrated Development Environment, which basically is an interface in which you can access your code like Java or Kotlin.
It also provides access to all the various tools required for the development. Android Studio provides you access to Android SDK libraries and APIs and also offers you to access the native operating system functions.

All that being said, you must remember that there are many options present for developing your Android Application. For instance, Unity is a very efficient cross-platform game development tool that also supports Android application development. Visual Studio with Xamarin makes for an incredible combination for developing cross-platform applications in C#. Android Studio is one of the best places for all the beginners to start (except for Android game development), especially as it provides you with all these increased resources and tools in one place.

Create a new project

Once you have the Android Studio on your system, the next step is to start creating a new project. This is a simple task, but you’ll have to make some choices that will have to affect the development of your Android apps going forward.

Go to File> New > New Project. Here, you will be required to pick a “Project Template” to define the code and UI elements that you want to be included in your new app when it opens.
Here “Activity” stands for the “Screen” in your application. Hence, a project which shows “No Activity” will be empty, with the exception of the primary file structure.
On the other hand, the “Basic Activity” creates a start screen in your app interface and adds a button at the bottom with a hamburger menu to the top of the app when it’s loaded.

Do you need Java or Kotlin?

Now, as an Android Developer, you will be required to make an important decision of whether you’re going to learn Java or Kotlin. Both Google and Android studio support the two languages, but there are some differences between them.

Java has been supported by Google for a long time now, and that’s what many developers use to create Android applications. Java is among the most popular programming languages worldwide, making it a popular alternative for app developers who want to find a decent job in android application development. As the earliest Android programming language, there’s a little more preference for Java than Kotlin, though it’s not much.
Now, on the other hand, Kotlin has become Google’s favourite choice for developing Android apps. It is the default when you set up a new application, and it can become more common in the future. Kotlin is much easier to deal with, too, if you’re a relative novice. For such reasons, Kotlin is probably the preferred language for Android app developers who are learning for fun, or who have no vision to expand on other platforms. However, if you want to learn app development on a professional level, then Java is best for you.

The lowest version of Android- Minimum SDK

You also have to take into account the Minimum SDK. That’s the lowest version of Android that you want your app to support.

The lesser you keep the number, the wider your audience size will be. You must also remember that there is a comparatively low adoption rate for the newest versions of the software, so trying to stick to the latest update will help stop a lot of users from trying to make it. If we depart the edition as default (Android 10), we only support 8.2 percent of devices!

That being said, only if you get a more current version, will you be able to acquire the latest features of Android. If you really like the sound of promoting the chat bubbles, you’ll want to stick to the latest version.

What do you need to know about the files?

The database that is opened is MainActivity.java or MainActivity.kt. It is the main File for the interaction that will define the behaviour of your app. Look left, and you’ll see this File can be found in MyApplication > app > src > main > java > com > companyname > myapplication.

The files used are essential for Android application development because they assist Android Studio and Gradle get everything that is required and build the app properly.

You’ll recognize that there’s a code written on the home page. It is known as “boilerplate code,” indicating that it is a code which is almost similar across separate app projects and is essentially required to make primary functions work. The boilerplate code is a set of instructions that you’re going to find yourself trying to type out again and again! One of Kotlin’s benefits is that it needs less boilerplate, which means that you will need less code on your screen if that’s what you’ve chosen.

What are the Layout Files?

The purpose of the code is to inform Android of the address where the associated layout file is situated. The Layout files are usually different from a Java/Kotlin file. It determines how an activity will look and enables you to add elements like buttons, browser windows, text and much more.

You can find this file at: MyApplication > app > src > res > layout.

It’s named as activity_main.xml. Remember that the files kept in the resource folder cannot use capital alphabets; they require the underscore symbol to differentiate various words. On double-clicking the File, the main window will open when you can edit your coding. Also, note that you can move between open files with clicking on the tabs on the top of the File.

You can check this File using the “Code” view, the “Design” view, or the split view which shows the window frames alongside each other. Use the buttons in the top right to switch mode.

With the design view, app developers can actually click and drag or drop various widgets to the screen window. With code view, you can see an XML script load. Hence, the whole script will be updated when you create new widgets with the Design view. Similarly, you can adjust the characteristics for the widgets (also called “views”) over here and watch them in real-time through the Code view.

Within the majority of apps, you will be required to make a new Kotlin/Java file and an appropriate XML file every time you require a new activity. But for those who are confused: yes, that implies you will need to learn either Java or Kotlin and XML. It’s a bit of a task, but it also facilitates the process of app development in the long run.

Test your application

First and foremost, you are required to create a “Hello World” application while you get acquainted with any programming language that is new for you. Thankfully, that’s very easy to do in this case because that’s what the instructions or code that’s already in it does! If users take a look at the XML, it contains a small label saying: Hello World!

When you gander at the various controls on the top, you’ll see the small green play pointer. There’s a drop-down list menu on the left, with a device name in it. At the time of installing Android Studio, the system would also have installed a Virtual device manager along with an Android system image. In simple words, you’re supposed to have an Android emulator on and ready to get started! Then click on the green arrow, and you’ll be ready to launch it and preview your app! Make sure that this also lets you work with the replicated phone as if it were a capacitive screen.

You can start changing your virtual settings menu – such as Android version, screen size, space, etc. – by clicking on Tools > AVD Manager. Here you will also be able to download a new system image. You must ensure your device meets or exceeds the minimum SDK you set at startup.

Otherwise, you can simply plug a hardware server into your system and then use it to run a test on your new app. However, you’ll have to turn on Options Menu and enable USB Connection.

How to do a project using all these steps?

One of the preferred ways to understand how to develop Android apps is by practising and creating apps! That implies you’re supposed to take a shot at editing the code on your screen to see if you can make something unique with it.

Creating the message you are displaying is as simple as entering into your XML and changing the line that shows “Hello World!” to “Howdy World!”

However, what if you’d like to add a kind of immersive storyline to your work? In that scenario, you may decide to let the user click on the button to change the text.

android:id=”@+id/helloButton”

android:onClick=”onHelloButtonClick”

Give the name “helloButton” to the text label and set the method “onHelloButtonClick” to refer to the view. Hence, we will add that to our code.
Then, you can add the below-mentioned code to your MainActivity. If you notice any text appearing red as you type it, that means you will have to “import” the said code from the Android SDK.

public class MainActivity extends AppCompatActivity {

TextView helloButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
helloButton = (TextView) findViewById(R.id.helloButton);
}

public void onHelloButtonClick (View v) {
helloButton.setText(“Howdy World!”);
}
}

Click the red highlighted text and then press Alt+Enter and Android Studio will do this automatically for you. In short, this tells Android that you’re referring to a library that’s part of the Android SDK.
In this software, you first generate an “object” in the code called “helloButton.”
From within our “onCreate” method (everything inside the curly brackets), we tell Android that this object shows the button in our layout file.
The coding you put here is what’s going to run first when you initiate an app.

After that, we generate a method that will run whenever anyone clicks the button. Once that happens, we can change the data on that button. Note that once again, Kotlin needs considerably fewer lines to do the same thing!

Open the program, and you should see that now the text changes when you click the button!

When you’ve read through all that, you’ll have a general premise of how Java works, but all that’s left is to know how to put these skills into Android app development. To that end, it’s a great strategy to choose a project and then work on it.

Conclusion

The best approach is not to try to learn “all about Android app development” but to set your goals on an accurate first project. You will enjoy practising as you create new content and want to do new things, and achieving a plan will keep your learning fun and structured. You’re going to be a pro before you know it!