How to create android application in android studio

Build Your First Android App in Java

1. Welcome!

In this codelab, you’ll learn how to build and run your first Android app in the Java programming language. (If you’re looking for the Kotlin version of this codelab, you can go here.)

What you must know already

This codelab is written for programmers and assumes that you know either the Java or Kotlin programming language. If you are an experienced programmer and adept at reading code, you will likely be able to follow this codelab, even if you don’t have much experience with Java.

What you’ll learn

Use Android Studio and Java to write Android apps

You write Android apps in the Java programming language using an IDE called Android Studio. Based on JetBrains’ IntelliJ IDEA software, Android Studio is an IDE designed specifically for Android development.

Note: This version of the codelab requires Android Studio 3.6 or higher.

To work through this codelab, you will need a computer that can run Android Studio 3.6 or higher (or already has Android Studio 3.6 or higher installed).

2. Install Android Studio

Note: This version of the codelab requires Android Studio 3.6 or higher.

You can download Android Studio 3.6 from the Android Studio page.

Android Studio provides a complete IDE, including an advanced code editor and app templates. It also contains tools for development, debugging, testing, and performance that make it faster and easier to develop apps. You can use Android Studio to test your apps with a large range of preconfigured emulators, or on your own mobile device. You can also build production apps and publish apps on the Google Play store.

Note: Android Studio is continually being improved. For the latest information on system requirements and installation instructions, see the Android Studio download page.

Android Studio is available for computers running Windows or Linux, and for Macs running macOS. The OpenJDK (Java Development Kit) is bundled with Android Studio.

The installation is similar for all platforms. Any differences are noted below.

Troubleshooting: If you run into problems with your installation, see the Android Studio release notes or Troubleshoot Android Studio.

3. Task: Create your first project

In this step, you will create a new Android project for your first app. This simple app displays the string «Hello World» on the screen of an Android virtual or physical device.

Here’s what the finished app will look like:

What you’ll learn

Step 1: Create a new project

After these steps, Android Studio:

Step 2: Get your screen set up

When your project first opens in Android Studio, there may be a lot of windows and panes open. To make it easier to get to know Android Studio, here are some suggestions on how to customize the layout.

At this point, your screen should look a bit less cluttered, similar to the screenshot shown below.

Step 3: Explore the project structure and layout

The upper left of the Android Studio window should look similar to the following diagram:

Based on you selecting the Basic Activity template for your project, Android Studio has set up a number of files for you. You can look at the hierarchy of the files for your app in multiple ways, one is in Project view. Project view shows your files and folders structured in a way that is convenient for working with an Android project. (This does not always match the file hierarchy! To see the file hierarchy, choose the Project files view by clicking (3).)

In the Project > Android view you see three or four top-level folders below your app folder: manifests, java, java (generated) and res. You may not see java (generated) right away.

This folder contains AndroidManifest.xml . This file describes all the components of your Android app and is read by the Android runtime system when your app is executed. 2. Expand the java folder. All your Java language files are organized here. The java folder contains three subfolders:

com.example.myfirstapp: This folder contains the Java source code files for your app.

com.example.myfirstapp (androidTest): This folder is where you would put your instrumented tests, which are tests that run on an Android device. It starts out with a skeleton test file.

com.example.myfirstapp (test): This folder is where you would put your unit tests. Unit tests don’t need an Android device to run. It starts out with a skeleton unit test file. 3. Expand the res folder. This folder contains all the resources for your app, including images, layout files, strings, icons, and styling. It includes these subfolders:

drawable: All your app’s images will be stored in this folder.

menu: This folder contains XML files describing any menus in your app.

mipmap: This folder contains the launcher icons for your app.

navigation: This folder contains the navigation graph, which tells Android Studio how to navigate between different parts of your application.

values: This folder contains resources, such as strings and colors, used in your app.

Step 4: Create a virtual device (emulator)

In this task, you will use the Android Virtual Device (AVD) manager to create a virtual device (or emulator) that simulates the configuration for a particular type of Android device.

The first step is to create a configuration that describes the virtual device.

Note: System images can take up a large amount of disk space, so just download what you need.

The AVD Manager now shows the virtual device you added.

Step 5: Run your app on your new emulator

If you get a dialog box stating «Instant Run requires that the platform corresponding to your target device (Android N. ) is installed» go ahead and click Install and continue.

The emulator starts and boots just like a physical device. Depending on the speed of your computer, this may take a while. You can look in the small horizontal status bar at the very bottom of Android Studio for messages to see the progress.

Messages that might appear briefly in the status bar

Gradle build running

Waiting for target device to come on line

Managing Projects from Android Studio

In this document

Android Studio provides graphical tools for creating and managing Android projects, which contain everything that define your Android apps, from app source code to build configurations and test code. Each project contains one or more different types of modules, such as application modules, library modules, and test modules.

This guide explains how to create Android projects and different modules using Android Studio. For more information about the Android project structure and module types, read Managing Projects Overview.

Creating an Android Project

Android Studio makes it easy to create Android apps for several form factors, such as phone, tablet, TV, Wear, and Google Glass. The New Project wizard lets you choose the form factors for your app and populates the project structure with everything you need to get started.

Follow the steps in this section to create a project in Android Studio.

Step 1: Create a New Project

If you didn’t have a project opened, Android Studio shows the Welcome screen. To create a new project, click New Project.

If you had a project opened, Android Studio shows the development environment. To create a new project, click File > New Project.

The next window lets you configure the name of your app, the package name, and the location of your project.

Figure 1. Choose a name for your project.

Enter the values for your project then click Next.

Step 2: Select Form Factors and API Level

The next window lets you select the form factors supported by your app, such as phone, tablet, TV, Wear, and Google Glass. The selected form factors become the application modules within the project. For each form factor, you can also select the API Level for that app. To get more information, click Help me choose.

Figure 2. Select the API Level.

The API Level window shows the distribution of mobile devices running each version of Android, as shown in figure 3. Click on an API level to see a list of features introduced in the corresponding version of Android. This helps you choose the minimum API Level that has all the features that your apps needs, so you can reach as many devices as possible. Then click OK.

Figure 3. Choose form factors for your app.

Then, on the Form Factors Window, click Next.

Step 3: Add an Activity

The next screen lets you select an activity type to add to your app, as shown in figure 4. This screen displays a different set of activities for each of the form factors you selected earlier.

Figure 4. Add an activity to your app.

Choose an activity type then click Next.

Note: If you choose «Add No Activity», click Finish to create the project.

Step 4: Configure Your Activity

The next screen lets you configure the activity to add to your app, as shown in figure 5.

Figure 5. Choose a name for your activity.

Enter the activity name, the layout name, and the activity title. Then click Finish.

Step 5: Develop Your App

Android Studio creates the default structure for your project and opens the development environment. If your app supports more than one form factor, Android Studio creates a module folder with complete source files for each of them as shown in figure 6.

Figure 6. The default project structure for a mobile app.

Now you are ready to develop your app. For more information, see the following links:

Creating an Android Module

To create a new module, select File > New > Module. Select the desire module type then click Next to enter the basic module settings:

Note: You can manually change the minimum and target SDK for your module at any time: Double-click the module’s build.gradle in the Project Explorer, set the targetSdkVersion and targetSdkVersion in the defaultConfig section.

The wizard creates a new Android application module according to the options you have chosen.

Setting up a Library Module

A library module is a standard Android module, so you can create a new one in the same way as you would a new application module, using the New Module wizard and selecting Android Library as the module type. The created library module will appear in your project view along with the other modules.

You can easily change an existing application module to a library module by changing the plugin assignment in the build.gradle file to com.android.library.

Adding a dependency on a library module

The library dependency can be declared in the module’s manifest file or in the GameActivity :

To add the dependency declaration to the build file, edit the build file for the app module ( app/build.gradle ) and add a dependency on the lib module:

In this example, the lib module can still be built and tested independently, and the build system creates an AAR package for it that you could reuse in other projects.

Note: The library settings in the app/build.gradle file will override any shared library resources declared in the manifest file.

Referencing a library module

If you are developing an application and want to include the shared code or resources from a library module, you can also do so easily by adding a reference to the library module in the module’s dependency page.

To add a reference to a library module, follow these steps:

If you are adding references to multiple libraries, you can set their relative priority (and merge order) by selecting a library and using the Up and Down controls. The tools merge the referenced libraries with your application starting from lowest priority (bottom of the list) to highest (top of the list). If more than one library defines the same resource ID, the tools select the resource from the library with higher priority. The application itself has highest priority and its resources are always used in preference to identical resource IDs defined in libraries.

Android Studio rebuilds the module, including the contents of the library module the next time the project or module is built.

Declaring library components in the manifest file

, and so on, as well as

Declarations should reference the library components by their fully-qualified package names, where appropriate.

For example, the TicTacToeMain example application declares the library activity GameActivity like this:

For more information about the manifest file, see the documentation for AndroidManifest.xml.

Using the Android Project View

The Android project view in Android Studio shows a flattened version of your project’s structure that provides quick access to the key source files of Android projects and helps you work with the new Gradle-based build system. The Android project view:

Use the Android Project View

The Android project view is enabled by default and shows all the build files at the top level of the project hierarchy under Gradle Scripts. The project module appears as a folder at the top level of the project hierarchy and contains these three elements at the top level:

Notice how the Android project view groups all instances of the ic_launcher.png resource for different screen densities under the same element.

Note: The Android project view shows a hierarchy that helps you work with Android projects by providing a flattened structure that highlights the most commonly used files while developing Android applications. However, the project structure on disk differs from this representation and maintains the traditional project structure.

Figure 10: Android and Traditional project view

My First App: How to Create Your First Android App Step by Step

To create a native Android app, one that can directly use all the features and functionality available on an Android phone or tablet, you need to use the Android platform’s Java API framework. This is the API that allows you to perform common tasks such as drawing text, shapes, and colors on the screen, playing sounds or videos, and interacting with a device’s hardware sensors. Over the years, the Android API framework has evolved to become more stable, intuitive, and concise. As a result, being an Android developer today is easier than ever—even more so if you use Android Studio, the official tool for working with the framework.

In this tutorial, I’ll show you how to create your first Android app. While doing so, I’ll also introduce you to important Android-specific concepts such as views, layouts, and activities.

We’ll be starting from scratch to create a very simple app in this tutorial. If you prefer writing less code or need to develop your app as quickly as possible, however, consider using one of the native Android app templates available on CodeCanyon.

Using an app template, you can have a polished, ready-to-publish app in just a matter of hours. You can learn how to use an Android app template by referring to the following tutorial:

Prerequisites

To be able to follow along, you’ll need:

If you don’t have Android Studio, do refer to the following tutorial to learn how to install and configure it:

1. Create a New Project

You’ll need an Android Studio project to design, develop, and build your app. So launch Android Studio and click on the Start a new Android Studio project button.

On the next screen, choose Add No Activity because we don’t want to use any of the templates offered by Android Studio. Then press Next to proceed.

You’ll now see a form where you can enter important details about your app, such as its name and package name. The name is, of course, the name your users will see on their phones when they install your app.

The package name, on the other hand, is a unique identifier for your app on Google Play. You must follow the Java package naming conventions while specifying it. For example, if your app’s name is MyFirstApp and you work for an organization whose website address is example.com, the package name would ideally be «com.example.myfirstapp».

Next, you must decide the programming language you want to use while coding the app. For now, select Java and press Finish.

Android Studio will now take a minute or two to generate and configure the project.

2. Create an Activity

An activity is one of the most important components of an Android app. It is what allows you to create and display a user interface to your users. An app can have one or more activities, each allowing the user to perform an action. For example, an email client app can have three activities: one for the user to sign up, one to sign in, and one to compose an email.

To keep this tutorial simple, we’ll be creating an app with just one activity. To create the activity, in the Project panel of Android Studio, right-click on app and select New > Activity > Empty Activity.

In the dialog that pops up, type in MainActivity as the name of the activity, check the Launcher Activity option, and press Finish.

Checking the Launcher Activity option is important because it is what allows your users to open the activity using an Android launcher. As such, a launcher activity serves as an entry point to your app.

3. Create a Layout

Each activity usually has at least one layout associated with it. When you created your activity in the previous step, you also generated an empty layout for it. To take a look at it, open the activity_main.xml file.

An activity’s layout primarily consists of views and view groups. A view, sometimes referred to as a widget, is an individual component of your user interface. Buttons, text fields, labels, and progress bars are common examples of views. A view group is a component that can serve as a container for views. Usually, view groups also help you position and set the dimensions of your views.

ConstraintLayout is one of the most powerful and flexible view groups available today. By default, it is the root node of your activity’s layout XML file. It looks like this:

We’ll be creating a simple clock app in this tutorial. In addition to the local time, it will be able to show the current time in two different countries: India and Germany.

To allow the user to choose the country they’re interested in, our layout will have two Button views, one for Germany, and one for India. And to actually show the time, our layout will have a TextClock view.

Accordingly, add the following code inside the ConstraintLayout :

Note that each view must have the layout_width and layout_height properties. They decide how large the view is. Other properties such as layout_constraintBottom_toBottomOf and layout_constraintLeft_toLeftOf are necessary to position the view. With the above code, the TextClock view will be placed at the center of the screen, and both the Button views towards the bottom of the screen.

Also note that each Button view has an onClick property. This property is used to assign click event handlers to the buttons.

The handlers don’t exist yet, but you can ask Android Studio to generate them for you. To do so, hover over the name of the handler until you see a red light bulb appear beside it. Then click on the light bulb and select the second option, the one with the yellow light bulb.

At this point, you can try pressing Shift-F10 to run the app. If there are no errors in your XML code, you should see something like this on your phone or emulator:

Although the buttons don’t work yet, the TextClock view should show the local time, updating itself every second.

4. Implement Event Handlers

When you generated event handlers for the two buttons, Android Studio added two methods to your activity’s Java file, MainActivity.java. If you open it, you should find the following code in it:

Inside the event handlers, all we need to do is change the time zone of the TextClock view. But how do you reference a view that’s in your layout XML file from inside your Java file? Well, you just use the findViewById() method.

Once you have a reference to the TextClock view, you can call its setTimeZone() method to change its time zone. So add the following code inside the onClickGermany() method:

Similarly, add the following code inside the onClickIndia() method:

If you’re wondering what R is, it’s an auto-generated class that contains, among other things, the IDs of all the views you have in your layouts. The findViewById() method expects you to use this class while passing an ID to it.

At this point, you can press Shift-F10 again to re-run the app. You should now be able to click on the buttons to change the clock’s time zone.

Conclusion

You just created your first fully functional, native app for Android! I encourage you to make a few changes to it. For instance, you could try using other time formats or time zones. You could also try changing the positions of the buttons and the clock view.

There are dozens of views and view groups you can use to create your apps. Do refer to the official documentation to learn about them.

Android App Templates and UI Kits From CodeCanyon

You may have noticed that our app looks very plain and simple. That’s because we’re using the default theme, without applying any styles to our views. CodeCanyon is full of Android UI kits that offer beautiful, hand-crafted styles you can apply to your views.

The kits generally also have several custom views and layouts. You can refer to the following articles to learn more about them:

Getting Started With Android Studio

Android Studio is a fairly new IDE (Integrated Development Environment) made available for free by Google to Android developers. Android Studio is based on IntelliJ IDEA, an IDE that also offers a good Android development environment. In this tutorial, I’ll show you how to create a new Android project and take advantage of the features that Android Studio has to offer.

When you’re just getting started with Android Studio, it can be very helpful to use an Android app template. You can find over a thousand of them for sale on Envato Market:

Android app templates for sale on Envato Market

1. Project Setup

Before you start exploring Android Studio, you’ll first need to download and install it. Note that you need to have JDK 6 or higher installed. If you’re on Windows, launch the .exe file and follow the steps of the setup wizard. If you’re running OS X, mount the disk image by double-clicking it and drag Android Studio to your Applications folder.

If you’ve successfully completed the above steps, then your development environment should be set up correctly. You’re now ready to create your first Android application using Android Studio. When you launch Android Studio for the first time, you should be presented with a welcome screen, offering you a number of choices to get you started.

In this tutorial, we’re going to choose the New Project option. However, you can choose Import Project if you’d like to import a project from, for example, Eclipse, into Android Studio. Android Studio will convert the Eclipse project to an Android Studio project, adding the necessary configuration files for you.

If you select Open Project from the list of options, you can open projects created with either Android Studio or IntelliJ IDEA. By choosing Check out from Version Control, you can check out a copy of a project that’s under version control. This is a great way to quickly get up to speed with an existing project.

To get us started, choose New Project from the list of options. This will show you a list of options to configure your new project. In this tutorial, we’re going to create a simple application to show you some of Android Studio’s most important features. I’m sure you agree that there’s no better name for our project than HelloWorld.

As you can see in the above screenshot, I’ve named my application HelloWorld and set the module name to HelloWorld. If you’re unfamiliar with IntelliJ IDEA, you may be wondering what a module is. A module is a discrete unit of functionality that can be compiled, run, tested, and debugged independently. Modules contain source code, build scripts, and everything else required for their specific task.

When creating a new project, you can also set the package name of the project. By default, Android Studio sets the last element of the project’s package name to the name of the module, but you can change it to whatever you want.

The other settings are the project’s location on your machine, the minimum and target SDK, the SDK your project will be compiled with, and the project’s theme. You can also tell Android Studio to create an Activity class and a custom launch icon for you, and whether the project supports GridLayout, Fragments, a Navigation Drawer, or an Action Bar.

We won’t create a custom icon for this application so you can uncheck the checkbox labeled Create custom launch icon. Click Next to continue setting up your project.

Because we checked the checkbox Create activity in the previous step, you are asked to configure the Activity class Android Studio will create for you.

Since we’ll be starting with a blank Activity class, you can click Next to proceed to the next step in the setup process in which you’re asked to name the Activity class, the main layout, and the fragment layout. You can also set the navigation type, which we’ll leave at None for this project. Take a look at the next screenshot to see what your settings should look like.

After clicking Finish, you’ll be presented with Android Studio’s user interface with the project explorer on the left and the workspace on the right. With your project set up in Android Studio, it’s time to explore some of the key features of Android Studio.

2. Android Virtual Devices

An Android Virtual Device or AVD is an emulator configuration, allowing you to model an Android device. This makes running and testing applications on a wide range of devices much easier. With an Android Virtual Device, you can specify the hardware and software the Android Emulator needs to emulate.

The preferred way to create an Android Virtual Device is through the AVD Manager, which you can access in Android Studio by selecting Android > AVD Manager from the Tools menu.

If you’re development environment is set up correctly, the Android Virtual Device Manager should look similar to the screenshot below.

To create a new AVD, click New. on the right, give the AVD a name, and configure the virtual device as shown below. Click OK to create your first AVD.

To use your newly created AVD, select it from the list in the AVD manager, and click Start. on the right. If your AVD is set up correctly, the Android Emulator should launch as shown in the screenshot below.

With the Android Emulator up and running, it’s time to launch your application by selecting Run ‘helloworld’ from the Run menu. That’s how easy it is to run an application in the Android Emulator.

3. Live Layout

Android Studio’s live layout feature lets you preview your application’s user interface without the need to run it on a device or the emulator. The live layout feature is a powerful tool that will literally save you hours. Viewing your application’s user interface is much faster using live layouts.

To work with live layouts, double-click the XML layout file and select the Text tab at the bottom of the workspace. Select the Preview tab on the right of the workspace to preview the current layout. Any changes you make to the XML layout will be reflected in the preview on the right. Take a look at the screenshot below to get a better idea of this neat feature.

There are a number of other advantages of the live layout feature that are worth pointing out. You can, for example, create a variation of the XML layout you’re currently working on by selecting an option from the first menu in the Preview pane. You can, for example, create separate views for portrait and landscape and Android Studio will create the necessary folders and files for you.

The second menu in the Preview pane lets you change the size of the device shown in the Preview pane. The third menu lets you change the orientation of the device shown in the Preview pane, which makes it easy to see how a layout looks in different orientations and using different themes.

The fourth menu in the Preview pane gives you easy access to the Activity or fragment in which the layout is used. The Preview pane also lets you change the language used in the live layout to make it easy to preview a layout in different languages. The rightmost menu lets you change the API version.

The Preview pane also includes controls to zoom in on the layout, refresh the Preview pane, or take a screenshot.

4. Templates

Android Studio provides developers with a number of templates to speed up development. These templates automatically create an Activity and the necessary XML files. You can use these templates to create a basic Android application, which you can then run on a device or in the emulator.

You can also select Image Asset from the menu, which will launch a wizard that guides you through the creation process. Let me show you how to create a new Activity based on the Login Activity template. Select the Login Activity option from the list of Activity templates to fire up the wizard.

As you can see in the above screenshot, I’ve named the Activity LoginActivity, set the Layout Name to activity_login, given the Activity a title of Sign In. The checkbox labeled Include Google+ sign in is checked by default. Uncheck it since we won’t be using this feature in our example.

The next step is to set up the new Activity in the manifest file so it’s used as the main Activity when the application launches. As you can see in manifest file below, the LoginActivity class has its own activity node.

When you build and run your application in the emulator, you should see a screen similar to the one shown below. This means that we’ve successfully replaced the blank Activity class with the newly created LoginActivity class.

5. Lint Tools

Testing your code is one thing, but it’s equally important to apply best practices when writing code. This will improve performance and the overall stability of your application. It’s also much easier to maintain a properly structured project.

Android Studio’s includes Android Lint, a static analyzer that analyzes your project’s source code. It can detect potential bugs and other problems in your code that are the compiler may overlook.

The below screenshot, for example, tells us that the LinearLayout in this layout is of no use. The nice thing about Android Lint is that it gives you a reason for the warning or error, which makes it easier to fix or resolve.

It’s good practice to run Android Studio’s lint tool from time to time to check your project for potential problems. The lint tool will even tell you if you have duplicate images or translations.

To run the lint tool, select Inspect Code… from the Analyze menu in Android Studio to start the process. When Android Studio has finished inspect your project, it will present you with the results at the bottom of the window. Note that in addition to Android Lint, Android Studio performs a number of other checks as well. Simply double-click an issue to navigate to the file in which the problem is located.

6. Rich Layout Editor

Android Studio has a rich layout editor in which you can drag and drop user interface components. You can also preview layouts on multiple screen configurations as we saw earlier in this tutorial.

The rich layout editor is very straightforward to use. We first need a layout to work with. Navigate to the layout folder in your project’s res folder, right-click the layout folder, and select New > Layout resource file from the menu that appears.

Give the new layout a name, set its root element, and click OK. Android Studio will automatically open the layout in the editor on the right.

At the bottom of the editor, you should see two tabs, Design and Text. Clicking the Text tab brings up the editor, allowing you to make changes to the currently selected layout.

Clicking the Design tab brings up another editor that shows you a preview of the layout. To add a widget to the layout, drag it from the list of widgets on the left to the layout on the right. It’s that simple.

Conclusion

In this tutorial, we’ve taken a brief look at some of the key features of Android Studio. It is very similar to IntelliJ IDEA, but it contains a number of important enhancements that make Android development easier, faster, and more enjoyable.

If you want to speed things up even more, try using an Android app template from Envato Market.

Build Your First Android App in Kotlin

1. Welcome!

In this codelab, you’ll learn how to build and run your first Android app in the Kotlin programming language. (If you’re looking for the Java version of this codelab, you can go here.) Kotlin is a statically typed programming language that runs on the JVM and is completely interoperable with the Java programming language. Kotlin is an officially supported language for developing Android apps, along with Java.

What you must know already

This codelab is written for programmers and assumes that you know either the Java or Kotlin programming language. If you are an experienced programmer and adept at reading code, you will likely be able to follow this codelab, even if you don’t have much experience with Kotlin.

What you’ll learn

Use Android Studio and Kotlin to write Android apps

You write Android apps in Kotlin or in the Java programming language using an IDE called Android Studio. Based on JetBrains’ IntelliJ IDEA software, Android Studio is an IDE designed specifically for Android development.

Note: This version of the codelab requires Android Studio 3.6 or higher.

To work through this codelab, you will need a computer that can run Android Studio 3.6 or higher (or already has Android Studio 3.6 or higher installed).

2. Install Android Studio

Note: This version of the codelab requires Android Studio 3.6 or higher.

You can download Android Studio 3.6 from the Android Studio page.

Android Studio provides a complete IDE, including an advanced code editor and app templates. It also contains tools for development, debugging, testing, and performance that make it faster and easier to develop apps. You can use Android Studio to test your apps with a large range of preconfigured emulators, or on your own mobile device. You can also build production apps and publish apps on the Google Play store.

Note: Android Studio is continually being improved. For the latest information on system requirements and installation instructions, see the Android Studio download page.

Android Studio is available for computers running Windows or Linux, and for Macs running macOS. The OpenJDK (Java Development Kit) is bundled with Android Studio.

The installation is similar for all platforms. Any differences are noted below.

Troubleshooting: If you run into problems with your installation, see the Android Studio release notes or Troubleshoot Android Studio.

3. Task: Create your first project

In this step, you will create a new Android project for your first app. This simple app displays the string «Hello World» on the screen of an Android virtual or physical device.

Here’s what the finished app will look like:

What you’ll learn

Step 1: Create a new project

After these steps, Android Studio:

Step 2: Get your screen set up

When your project first opens in Android Studio, there may be a lot of windows and panes open. To make it easier to get to know Android Studio, here are some suggestions on how to customize the layout.

At this point, your screen should look a bit less cluttered, similar to the screenshot shown below.

Step 3: Explore the project structure and layout

The upper left of the Android Studio window should look similar to the following diagram:

Based on you selecting the Basic Activity template for your project, Android Studio has set up a number of files for you. You can look at the hierarchy of the files for your app in multiple ways, one of which is in Project view (2). Project view shows your files and folders structured in a way that is convenient for working with an Android project. (This does not always match the file hierarchy! To see the file hierarchy, choose the Project files view by clicking (3).)

In the Project > Android view you see three or four top-level folders below your app folder: manifests, java, java (generated) and res. You may not see java (generated) right away.

This folder contains AndroidManifest.xml . This file describes all the components of your Android app and is read by the Android runtime system when your app is executed. 2. Expand the java folder. All your Kotlin language files are organized here; Android projects keep all Kotlin language files in this folder, together with any Java sources. The java folder contains three subfolders:

com.example.myfirstapp (or the domain name you have specified): This folder contains the Kotlin source code files for your app.

com.example.myfirstapp (androidTest): This folder is where you would put your instrumented tests, which are tests that run on an Android device. It starts out with a skeleton test file.

com.example.myfirstapp (test): This folder is where you would put your unit tests. Unit tests don’t need an Android device to run. It starts out with a skeleton unit test file. 3. Expand the res folder. This folder contains all the resources for your app, including images, layout files, strings, icons, and styling. It includes these subfolders:

drawable: All your app’s images will be stored in this folder.

menu: This folder contains XML files describing any menus in your app.

mipmap: This folder contains the launcher icons for your app.

navigation: This folder contains the navigation graph, which tells Android Studio how to navigate between different parts of your application.

values: Contains resources, such as strings and colors, used in your app.

Step 4: Create a virtual device (emulator)

In this task, you will use the Android Virtual Device (AVD) manager to create a virtual device (or emulator) that simulates the configuration for a particular type of Android device.

The first step is to create a configuration that describes the virtual device.

Note: System images can take up a large amount of disk space, so just download what you need.

The AVD Manager now shows the virtual device you added.

Step 5: Run your app on your new emulator

If you get a dialog box stating «Instant Run requires that the platform corresponding to your target device (Android N. ) is installed» go ahead and click Install and continue.

The emulator starts and boots just like a physical device. Depending on the speed of your computer, this may take a while. You can look in the small horizontal status bar at the very bottom of Android Studio for messages to see the progress.

Messages that might appear briefly in the status bar

Gradle build running

Waiting for target device to come on line