<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="HelloWorld.MainPage">

    <StackLayout>
        <Label Text="Hola Mundo"
               VerticalOptions="CenterAndExpand" 
               HorizontalOptions="CenterAndExpand" />
    </StackLayout>

</ContentPage>

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="HelloWorld.MainPage">

    <StackLayout>
        <Label Text="Ingrese su nombre:" />
        <Entry x:Name="nameEntry" Placeholder="Nombre" />
        <Button Text="Saludar" Clicked="OnButtonClicked" />
        <Label x:Name="greetingLabel" />
    </StackLayout>

</ContentPage>

using Xamarin.Forms;

namespace HelloWorld
{
    public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
        }

        private void OnButtonClicked(object sender, EventArgs e)
        {
            string name = nameEntry.Text;
            greetingLabel.Text = $"Hola, {name}!";
        }
    }
}

// MainPage.xaml.cs
private async void OnNavigateButtonClicked(object sender, EventArgs e)
{
    await Navigation.PushAsync(new SecondPage());
}

// SecondPage.xaml
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="HelloWorld.SecondPage">

    <StackLayout>
        <Label Text="Esta es la segunda página" />
    </StackLayout>

</ContentPage>

using Xamarin.Essentials;

public async Task GetLocationAsync()
{
    try
    {
        var location = await Geolocation.GetLastKnownLocationAsync();
        if (location != null)
        {
            Console.WriteLine($"Latitude: {location.Latitude}, Longitude: {location.Longitude}");
        }
    }
    catch (Exception ex)
    {
        // Handle exception
    }
}

// MainPage.xaml
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="TodoApp.MainPage">

    <StackLayout>
        <Button Text="Agregar Tarea" Clicked="OnAddTaskClicked" />
        <ListView x:Name="tasksListView" />
    </StackLayout>

</ContentPage>

// MainPage.xaml.cs
public partial class MainPage : ContentPage
{
    private List<string> tasks = new List<string>();

    public MainPage()
    {
        InitializeComponent();
    }

    private async void OnAddTaskClicked(object sender, EventArgs e)
    {
        var addTaskPage = new AddTaskPage();
        addTaskPage.TaskAdded += (s, task) =>
        {
            tasks.Add(task);
            tasksListView.ItemsSource = null;
            tasksListView.ItemsSource = tasks;
        };
        await Navigation.PushAsync(addTaskPage);
    }
}

// AddTaskPage.xaml
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="TodoApp.AddTaskPage">

    <StackLayout>
        <Entry x:Name="taskEntry" Placeholder="Nueva Tarea" />
        <Button Text="Agregar" Clicked="OnAddButtonClicked" />
    </StackLayout>

</ContentPage>

// AddTaskPage.xaml.cs
public partial class AddTaskPage : ContentPage
{
    public event EventHandler<string> TaskAdded;

    public AddTaskPage()
    {
        InitializeComponent();
    }

    private void OnAddButtonClicked(object sender, EventArgs e)
    {
        var task = taskEntry.Text;
        TaskAdded?.Invoke(this, task);
        Navigation.PopAsync();
    }
}