Build a simple android expense tracker app

Introduction

Building a simple Android expense tracker app is a great way to manage your money. In this guide, we will walk you through the steps needed to create an easy app. You’ll learn how to add expenses, view your spending, and keep track of your budget. Let’s get started!

Why Build an Expense Tracker App?

Here’s the thing: tracking your expenses can help you understand where your money goes. This can save you from overspending and help you stick to a budget. By creating your own app, you can tailor it to your needs and preferences.

What You Need

Before we start coding, make sure you have the following:

• A computer with Android Studio installed
• Basic knowledge of Java or Kotlin
• A device or emulator to test your app

Setting Up Your Project

To begin, open Android Studio and create a new project. Here are the steps:

1. Select "New Project".
2. Choose "Empty Activity".
3. Name your project "ExpenseTracker".
4. Choose a package name, like "com.example.expensetracker".
5. Pick Java or Kotlin as your programming language.
6. Click "Finish".

Designing the User Interface

Now, it's time to design how your app will look. Open the activity_main.xml file and add the following elements:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <EditText
        android:id="@+id/editTextExpense"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter expense"/>

    <Button
        android:id="@+id/buttonAdd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Add Expense"/>

    <TextView
        android:id="@+id/textViewTotal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

This layout has an input field, a button, and a place to show your total expenses.

Adding Functionality

Next, let’s make the button work. Open the MainActivity.java (or MainActivity.kt if using Kotlin) file and add the following code:

public class MainActivity extends AppCompatActivity {
    private EditText editTextExpense;
    private TextView textViewTotal;
    private double totalExpenses = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        editTextExpense = findViewById(R.id.editTextExpense);
        textViewTotal = findViewById(R.id.textViewTotal);
        Button buttonAdd = findViewById(R.id.buttonAdd);

        buttonAdd.setOnClickListener(v -> {
            String expenseText = editTextExpense.getText().toString();
            if (!expenseText.isEmpty()) {
                double expense = Double.parseDouble(expenseText);
                totalExpenses += expense;
                textViewTotal.setText("Total: $" + totalExpenses);
                editTextExpense.setText("");
            }
        });
    }
}

This code initializes the views and sets an action for the button. When clicked, it adds the expense from the input field to the total.

Testing Your App

Now it’s time to test your app. Click the "Run" button in Android Studio and select your device or emulator. Try adding expenses and see the total update. Here's what this really means: you have a basic app that tracks your expenses!

Next Steps

You've built a simple expense tracker. Here are some ideas to improve it:

• Add a list to show all expenses
• Include categories for your expenses
• Store data in a local database
• Add the ability to edit or delete expenses

Conclusion

Creating your own Android expense tracker app can be fun and helpful. It gives you control over your finances and teaches you about app development. Now that you've learned the basics, you can expand this project as much as you want. Happy coding!