{"id":3955,"date":"2023-11-04T23:13:57","date_gmt":"2023-11-04T23:13:57","guid":{"rendered":"http:\/\/localhost:10003\/how-to-build-a-todo-list-app-with-kotlin-and-android-studio\/"},"modified":"2023-11-05T05:48:26","modified_gmt":"2023-11-05T05:48:26","slug":"how-to-build-a-todo-list-app-with-kotlin-and-android-studio","status":"publish","type":"post","link":"http:\/\/localhost:10003\/how-to-build-a-todo-list-app-with-kotlin-and-android-studio\/","title":{"rendered":"How to Build a Todo List App with Kotlin and Android Studio"},"content":{"rendered":"
In this tutorial, we will learn how to build a Todo List app using Kotlin and Android Studio. We will create a simple app that allows users to create and manage their todo list.<\/p>\n
Before we begin, make sure you have the following installed on your system:<\/p>\n
Let’s start by creating a new project in Android Studio:<\/p>\n
Next, let’s design the user interface for our app:<\/p>\n
activity_main.xml<\/code> file located in the res\/layout<\/code> directory.<\/li>\n- Replace the default contents of the file with the following XML code:<\/li>\n<\/ol>\n
<LinearLayout \n xmlns_android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\n xmlns_tools=\"http:\/\/schemas.android.com\/tools\"\n android_layout_width=\"match_parent\"\n android_layout_height=\"match_parent\"\n android_orientation=\"vertical\"\n android_padding=\"16dp\"\n tools_context=\".MainActivity\">\n\n <EditText\n android_id=\"@+id\/todoEditText\"\n android_layout_width=\"match_parent\"\n android_layout_height=\"wrap_content\"\n android_hint=\"Enter a todo item\" \/>\n\n <Button\n android_id=\"@+id\/addButton\"\n android_layout_width=\"wrap_content\"\n android_layout_height=\"wrap_content\"\n android_text=\"Add\" \/>\n\n <ListView\n android_id=\"@+id\/todosListView\"\n android_layout_width=\"match_parent\"\n android_layout_height=\"0dp\"\n android_layout_weight=\"1\" \/>\n\n<\/LinearLayout>\n<\/code><\/pre>\nThis layout consists of an EditText<\/code> view for entering a new todo item, a Button<\/code> for adding the item, and a ListView<\/code> to display the list of todo items.<\/p>\nStep 3: Create the Todo Item Model<\/h2>\n
Now, let’s create a data model for our todo items.<\/p>\n
\n- Right-click on the package name in the Project panel.<\/li>\n
- Select “New” -> “Kotlin Class” to create a new Kotlin class.<\/li>\n
- Enter “TodoItem” as the name and click “OK”.<\/li>\n
- Replace the contents of the newly created
TodoItem.kt<\/code> file with the following code:<\/li>\n<\/ol>\ndata class TodoItem(val name: String, val completed: Boolean)\n<\/code><\/pre>\nThis data class represents a todo item with a name and a completed flag.<\/p>\n
Step 4: Implement the Adapter<\/h2>\n
The next step is to implement an adapter class that will be used to populate the ListView<\/code> with the todo items.<\/p>\n\n- Right-click on the package name in the Project panel.<\/li>\n
- Select “New” -> “Kotlin Class” to create a new Kotlin class.<\/li>\n
- Enter “TodoListAdapter” as the name and click “OK”.<\/li>\n
- Replace the contents of the newly created
TodoListAdapter.kt<\/code> file with the following code:<\/li>\n<\/ol>\nimport android.content.Context\nimport android.view.LayoutInflater\nimport android.view.View\nimport android.view.ViewGroup\nimport android.widget.BaseAdapter\nimport kotlinx.android.synthetic.main.todo_item.view.*\n\nclass TodoListAdapter(private val context: Context, private val todoItems: List<TodoItem>) : BaseAdapter() {\n\n override fun getCount() = todoItems.size\n\n override fun getItem(position: Int) = todoItems[position]\n\n override fun getItemId(position: Int) = position.toLong()\n\n override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {\n val view = convertView ?: LayoutInflater.from(context).inflate(R.layout.todo_item, parent, false)\n\n val todoItem = todoItems[position]\n\n view.todoNameTextView.text = todoItem.name\n\n return view\n }\n}\n<\/code><\/pre>\nThis adapter class extends the BaseAdapter<\/code> class and overrides its methods to provide the required functionality. It takes a list of todo items as input and populates the ListView<\/code> with them.<\/p>\nStep 5: Implement the MainActivity<\/h2>\n
Now, let’s implement the MainActivity<\/code> class, which will be the main entry point of our app.<\/p>\n\n- Open the
MainActivity.kt<\/code> file located in the java<\/code> directory.<\/li>\n- Replace the default contents of the file with the following code:<\/li>\n<\/ol>\n
import androidx.appcompat.app.AppCompatActivity\nimport android.os.Bundle\nimport kotlinx.android.synthetic.main.activity_main.*\n\nclass MainActivity : AppCompatActivity() {\n\n private val todoItems = mutableListOf<TodoItem>()\n private lateinit var todoListAdapter: TodoListAdapter\n\n override fun onCreate(savedInstanceState: Bundle?) {\n super.onCreate(savedInstanceState)\n setContentView(R.layout.activity_main)\n\n todoListAdapter = TodoListAdapter(this, todoItems)\n todosListView.adapter = todoListAdapter\n\n addButton.setOnClickListener {\n val todoName = todoEditText.text.toString().trim()\n\n if (todoName.isNotEmpty()) {\n val todoItem = TodoItem(todoName, false)\n todoItems.add(todoItem)\n todoListAdapter.notifyDataSetChanged()\n todoEditText.text.clear()\n }\n }\n }\n}\n<\/code><\/pre>\nThis code sets the TodoListAdapter<\/code> as the adapter for the ListView<\/code> and binds the addButton<\/code> click event to add a new todo item to the list.<\/p>\nStep 6: Run the App<\/h2>\n
Finally, let’s run the app and test our todo list functionality.<\/p>\n
\n- Connect an Android device to your computer or start an emulator.<\/li>\n
- Click on the “Run” button in the Android Studio toolbar.<\/li>\n
- Select the target device and click “OK”.<\/li>\n
- After the app is installed, it will launch on your device.<\/li>\n<\/ol>\n
You should now see the app running on your device. You can enter a new todo item in the EditText<\/code> and click the “Add” button to add it to the list. The list will be updated with the new item, and you can scroll to view all the items.<\/p>\nCongratulations! You have successfully built a Todo List app with Kotlin and Android Studio.<\/p>\n
Conclusion<\/h2>\n
In this tutorial, we learned how to build a Todo List app using Kotlin and Android Studio. We created a simple app that allows users to create and manage their todo list. We covered topics such as designing the user interface, creating the data model, implementing the adapter, and writing the main activity code.<\/p>\n
You can further enhance this app by adding features like editing and deleting todo items, marking items as completed, and persisting the todo list data using a local database.<\/p>\n","protected":false},"excerpt":{"rendered":"
In this tutorial, we will learn how to build a Todo List app using Kotlin and Android Studio. We will create a simple app that allows users to create and manage their todo list. Prerequisites Before we begin, make sure you have the following installed on your system: Android Studio Continue Reading<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[548,259,547,10,550,552,258,549,551,2],"yoast_head":"\nHow to Build a Todo List App with Kotlin and Android Studio - Pantherax Blogs<\/title>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\t\n\t\n\t\n