Building Your First Android App (Without Sketchware)

  

Part 1: Creating a Simple App with Android Studio

Let’s Build a Simple App!

Now that your workspace is set up, it’s time to create your very first Android app. Think of it as building a very simple toy to see how everything works. We’re going to make an app that says “Hello, World!” when you open it.

Step 1: Start a New Project

1. Open Android Studio: You should see an option to start a new project. Click on it.
2. Choose a Template: Android Studio will show you some templates. Choose the one that says “Empty Activity.” This is like choosing a blank canvas to draw on.
3. Name Your Project: Give your project a name, like “HelloWorldApp,” and choose where to save it. Then, click “Finish.”

Step 2: Design the App’s Layout

1. Open the Layout Editor: Android Studio will take you to a screen where you can see your app’s layout. It’s a blank screen for now, but we’re going to add some text.
2. Add a TextView: On the left, you’ll see a palette with different UI components like buttons and text boxes. Drag a TextView from the palette onto the blank screen.
3. Change the Text: Click on the TextView, and in the properties panel on the right, find the “text” property. Change it to say “Hello, World!”

Step 3: Write the Code

1. Open MainActivity.java: On the left side of Android Studio, find and open the file called MainActivity.java. This is where we write the code that makes the app work.

2. Write the Code: Don’t worry, you don’t need to write much! Android Studio already puts some code there for you. Just make sure your code looks like this:

This code tells your app to show the layout you just designed when it starts.

Step 4: Run Your App

1. Connect Your Android Device: You can either use an Android phone or an emulator. If you have a phone, connect it to your computer with a USB cable and enable “Developer Options” and “USB Debugging.”
2. Click Run: In Android Studio, click the green “Run” button at the top. This will build your app and install it on your phone or emulator.
3. See Your App in Action: Once it’s done, your app will open, and you should see “Hello, World!” on the screen!

Part 2: Running and Testing Your App

Why Testing is Important

Imagine you’ve built a toy car, but you didn’t check if the wheels were on correctly. When you try to play with it, the wheels might fall off! Testing your app is just like checking your toy before you play with it. It makes sure everything works as it should.

How to Test Your App

• Try Different Actions: Open your app and tap on things, swipe, and try anything you can think of. See if it behaves the way you want it to.
• Use Different Devices: If you can, try your app on different phones or tablets to make sure it looks and works well on all of them.

What to Do if You Find a Problem

• Fix the Code: If something doesn’t work, go back to Android Studio and fix the code. Then, run your app again to see if it’s better.
• Use Logcat: Android Studio has a tool called Logcat that shows you messages from your app. If there’s a problem, Logcat can help you figure out what went wrong.