<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="TodoREST.TodoListPage" Title="Todo">
	<ContentPage.ToolbarItems>
		<ToolbarItem Text="+" Clicked="OnAddItemClicked">
			<ToolbarItem.Icon>
			<OnPlatform x:TypeArguments="FileImageSource" Android="plus.png" />
			</ToolbarItem.Icon>
		</ToolbarItem>
	</ContentPage.ToolbarItems>
	<ContentPage.Content>
		<ListView x:Name="listView" ItemSelected="OnItemSelected">
			<ListView.ItemTemplate>
				<DataTemplate>
					<ViewCell>
						<StackLayout Padding="20,0,0,0" HorizontalOptions="StartAndExpand" Orientation="Horizontal">
				<Label Text="{Binding Name}" VerticalTextAlignment="Center" />
				<Image Source="check.png" IsVisible="{Binding Done}" />
						</StackLayout>
					</ViewCell>
				</DataTemplate>
			</ListView.ItemTemplate>
		</ListView>
	</ContentPage.Content>
</ContentPage>

using Xamarin.Forms;

namespace TodoREST
{
    public partial class TodoListPage : ContentPage
    {
        bool alertShown = false;

        public TodoListPage()
        {
            InitializeComponent();
        }

        protected async override void OnAppearing()
        {
            base.OnAppearing();
            listView.ItemsSource = await App.TodoManager.GetTasksAsync();
        }

        void OnAddItemClicked(object sender, EventArgs e)
        {
            var todoItem = new TodoItem()
            {
                ID = Guid.NewGuid().ToString()
            };
            var todoPage = new TodoItemPage(true);
            todoPage.BindingContext = todoItem;
            Navigation.PushAsync(todoPage);
        }

        void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
        {
            var todoItem = e.SelectedItem as TodoItem;
            var todoPage = new TodoItemPage();
            todoPage.BindingContext = todoItem;
            Navigation.PushAsync(todoPage);
        }
    }
} 

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
			 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
			 x:Class="TodoREST.TodoItemPage" 
			 Title="Todo">
	<ContentPage.Content>
		<StackLayout VerticalOptions="StartAndExpand">
			<Label Text="Name" />
			<Entry x:Name="nameEntry" Text="{Binding Path=Name}" Placeholder="task name" />
			<Label Text="Notes" />
			<Entry x:Name="notesEntry" Text="{Binding Path=Notes}" />
			<Label Text="Done" />
			<Switch x:Name="doneSwitch" IsToggled="{Binding Path=Done}" />
			<Button Text="Save" Clicked="OnSaveActivated" />
			<Button Text="Delete" Clicked="OnDeleteActivated" />
			<Button Text="Cancel" Clicked="OnCancelActivated" />
		</StackLayout>
	</ContentPage.Content>
</ContentPage>

using System;
using TodoREST.Models;
using Xamarin.Forms;

namespace TodoREST
{
    public partial class TodoItemPage : ContentPage
    {
        bool isNewItem;

        public TodoItemPage(bool isNew = false)
        {
            InitializeComponent();
            isNewItem = isNew;
        }

        async void OnSaveActivated(object sender, EventArgs e)
        {
            var todoItem = (TodoItem)BindingContext;
            await App.TodoManager.SaveTaskAsync(todoItem, isNewItem);
            await Navigation.PopAsync();
        }

        async void OnDeleteActivated(object sender, EventArgs e)
        {
            var todoItem = (TodoItem)BindingContext;
            await App.TodoManager.DeleteTaskAsync(todoItem);
            await Navigation.PopAsync();
        }

        void OnCancelActivated(object sender, EventArgs e)
        {
            Navigation.PopAsync();
        }
    }
}

using TodoREST.Data;
using Xamarin.Forms;
    
public class App : Application
    {
        public static TodoItemManager TodoManager { get; private set; }

        public static ITextToSpeech Speech { get; set; }

        public App()
        {
            TodoManager = new TodoItemManager(new RestService());
            MainPage = new NavigationPage(new TodoListPage());
        }
    }