{"id":4252,"date":"2023-11-04T23:14:10","date_gmt":"2023-11-04T23:14:10","guid":{"rendered":"http:\/\/localhost:10003\/how-to-build-a-todo-list-app-with-csharp-and-xamarin\/"},"modified":"2023-11-05T05:47:55","modified_gmt":"2023-11-05T05:47:55","slug":"how-to-build-a-todo-list-app-with-csharp-and-xamarin","status":"publish","type":"post","link":"http:\/\/localhost:10003\/how-to-build-a-todo-list-app-with-csharp-and-xamarin\/","title":{"rendered":"How to Build a Todo List App with CSharp and Xamarin"},"content":{"rendered":"
In this tutorial, we will walk through the process of building a todo list app using C# and Xamarin. Xamarin is a cross-platform development framework that allows us to write applications for Android, iOS, and Windows using the .NET language. We will use Visual Studio as our IDE to develop and build the app.<\/p>\n
The app we are going to build will have the following functionality:
\n– Ability to add tasks to the todo list
\n– Ability to mark tasks as completed
\n– Ability to delete tasks from the todo list
\n– Ability to filter tasks based on their completion status<\/p>\n
By the end of this tutorial, you will have a functioning todo list app that you can run on Android and iOS devices.<\/p>\n
To follow along with this tutorial, you will need the following:<\/p>\n
Let’s start by creating a new Xamarin.Forms project in Visual Studio:<\/p>\n
Visual Studio will create a new Xamarin.Forms project with 3 projects: a shared .NET Standard library, an Android project, and an iOS project.<\/p>\n
Next, we will design the user interface for our app. Open the In this XAML code, we have a We also have an Next, let’s create a model class to represent a task. Right-click on the shared project and select “Add -> Class”. Name the class This class implements the Now, let’s create a view model class to manage the data and interaction with the UI. Right-click on the shared project and select “Add -> Class”. Name the class This view model class contains an Next, let’s update the code-behind file for the In the constructor, we set the We also handle the “Add” button click event to add a new task to the view model and clear the text input.<\/p>\n Now, let’s test the app on an Android device or emulator:<\/p>\n Once the app is running, you should be able to add tasks to the list and mark them as completed by tapping on the checkboxes.<\/p>\n Next, let’s test the app on an iOS device or simulator:<\/p>\n Once the app is running, you should see the same functionality as on the Android device or emulator.<\/p>\n In this tutorial, we have built a todo list app using C# and Xamarin. We learned how to create a user interface, implement a view model, and integrate the UI with the view model. We also tested the app on Android and iOS devices.<\/p>\n You can further enhance the app by adding features like task filtering, editing tasks, and persisting tasks using a local database. This tutorial serves as the foundation for building more complex Xamarin apps with C#. Happy coding!<\/p>\n","protected":false},"excerpt":{"rendered":" Introduction In this tutorial, we will walk through the process of building a todo list app using C# and Xamarin. Xamarin is a cross-platform development framework that allows us to write applications for Android, iOS, and Windows using the .NET language. We will use Visual Studio as our IDE to 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":[8,4,3,6,7,2,5],"yoast_head":"\nMainPage.xaml<\/code> file in the shared project and replace the existing XAML code with the following:<\/p>\n
<ContentPage \n xmlns_x=\"http:\/\/schemas.microsoft.com\/winfx\/2009\/xaml\"\n x_Class=\"TodoListApp.MainPage\"\n Title=\"Todo List\">\n\n <ContentPage.Content>\n <StackLayout>\n <ListView x_Name=\"taskListView\" ItemsSource=\"{Binding Tasks}\" \n HasUnevenRows=\"True\" SelectionMode=\"None\">\n <ListView.ItemTemplate>\n <DataTemplate>\n <ViewCell>\n <StackLayout Orientation=\"Horizontal\" Padding=\"10\">\n <CheckBox IsChecked=\"{Binding IsCompleted}\" \/>\n <Label Text=\"{Binding Description}\" VerticalTextAlignment=\"Center\" \/>\n <\/StackLayout>\n <\/ViewCell>\n <\/DataTemplate>\n <\/ListView.ItemTemplate>\n <\/ListView>\n\n <StackLayout Orientation=\"Horizontal\" Padding=\"10,0\">\n <Entry x_Name=\"taskEntry\" Placeholder=\"Enter task description\" \/>\n <Button Text=\"Add\" Clicked=\"OnAddClicked\" \/>\n <\/StackLayout>\n <\/StackLayout>\n <\/ContentPage.Content>\n<\/ContentPage>\n<\/code><\/pre>\n
ListView<\/code> control that will display our tasks. Each task is represented by a
ViewCell<\/code> containing a
CheckBox<\/code> to mark the task as completed and a
Label<\/code> to display the task description.<\/p>\n
Entry<\/code> control and a
Button<\/code> control at the bottom of the page, which will allow the user to add new tasks to the list.<\/p>\n
Step 3: Create the model class<\/h2>\n
TaskItem.cs<\/code> and replace the code with the following:<\/p>\n
using System.ComponentModel;\n\nnamespace TodoListApp\n{\n public class TaskItem : INotifyPropertyChanged\n {\n public event PropertyChangedEventHandler PropertyChanged;\n\n private string description;\n private bool isCompleted;\n\n public string Description\n {\n get { return description; }\n set\n {\n if (description != value)\n {\n description = value;\n OnPropertyChanged(nameof(Description));\n }\n }\n }\n\n public bool IsCompleted\n {\n get { return isCompleted; }\n set\n {\n if (isCompleted != value)\n {\n isCompleted = value;\n OnPropertyChanged(nameof(IsCompleted));\n }\n }\n }\n\n protected virtual void OnPropertyChanged(string propertyName)\n {\n PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));\n }\n }\n}\n<\/code><\/pre>\n
INotifyPropertyChanged<\/code> interface, which allows us to notify the UI when a property changes. It has two properties:
Description<\/code>, which represents the task description, and
IsCompleted<\/code>, which represents whether the task is completed or not.<\/p>\n
Step 4: Implement the view model<\/h2>\n
MainViewModel.cs<\/code> and replace the code with the following:<\/p>\n
using System.Collections.Generic;\nusing System.Collections.ObjectModel;\n\nnamespace TodoListApp\n{\n public class MainViewModel\n {\n public ObservableCollection<TaskItem> Tasks { get; } = new ObservableCollection<TaskItem>();\n\n public void AddTask(string description)\n {\n Tasks.Add(new TaskItem { Description = description });\n }\n }\n}\n<\/code><\/pre>\n
ObservableCollection<\/code> of
TaskItem<\/code> objects, which will store our tasks. It also has a method
AddTask<\/code> that adds a new task to the collection.<\/p>\n
Step 5: Update the code-behind file<\/h2>\n
MainPage<\/code> to integrate the view model with the UI. Open the
MainPage.xaml.cs<\/code> file and replace the code with the following:<\/p>\n
using Xamarin.Forms;\n\nnamespace TodoListApp\n{\n public partial class MainPage : ContentPage\n {\n private MainViewModel viewModel = new MainViewModel();\n\n public MainPage()\n {\n InitializeComponent();\n\n BindingContext = viewModel;\n }\n\n private void OnAddClicked(object sender, EventArgs e)\n {\n string description = taskEntry.Text;\n if (!string.IsNullOrWhiteSpace(description))\n {\n viewModel.AddTask(description);\n taskEntry.Text = string.Empty;\n }\n }\n }\n}\n<\/code><\/pre>\n
BindingContext<\/code> of the page to an instance of the
MainViewModel<\/code> class. This allows us to bind the
Tasks<\/code> property of the view model to the
ItemsSource<\/code> property of the
ListView<\/code> in the XAML code.<\/p>\n
Step 6: Test the app on Android<\/h2>\n
\n
Step 7: Test the app on iOS<\/h2>\n
\n
Conclusion<\/h2>\n