TA-2017 Calculo Média

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:AppCalculoMedia"
             x:Class="AppCalculoMedia.MainPage">
    <ScrollView>
        <StackLayout>
	<Label Text="Calculando seus gastos!"
           VerticalOptions="Center"
           HorizontalOptions="Center"
           FontSize="20"
           />
    <Label Text="Valor da Gasolina:"
           VerticalOptions="Center"
           HorizontalOptions="Center" />
    <Entry HorizontalOptions="FillAndExpand"
           x:Name="valorGasolina"
           Keyboard="{Binding Numerico}"/>

    <Label Text="Litros Abastecidos:"
           VerticalOptions="Center"
           HorizontalOptions="Center" />
    <Entry HorizontalOptions="FillAndExpand"
           x:Name="litrosAbastecidos"
           Keyboard="{Binding Numerico}"/>

    <Label Text="Km Rodados:"
           VerticalOptions="Center"
           HorizontalOptions="Center" />
    <Entry HorizontalOptions="FillAndExpand"
           x:Name="kmRodados"
           Keyboard="{Binding Numerico}"/>
    <Button Text="Calcular"
            HorizontalOptions="FillAndExpand"
            VerticalOptions="Center"
            Clicked="Calcular"/>
            <Label Text=""
                   x:Name="media"
           VerticalOptions="Center"
           HorizontalOptions="Center" />
            <Label Text="Total gasto"
                   x:Name="total"
           VerticalOptions="Center"
           HorizontalOptions="Center" />
        </StackLayout>
    </ScrollView>
</ContentPage>

---


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace AppCalculoMedia
{
	public partial class MainPage : ContentPage
	{
        public Keyboard Numerico { get; set; }
		public MainPage()
		{
			InitializeComponent();
            Numerico = Keyboard.Numeric;
            BindingContext = this;
		}
        public void Calcular (object sender, EventArgs eventArgs)
        {
            var valorG = valorGasolina.Text.ToString();
            var litrosA = litrosAbastecidos.Text.ToString();
            var kmR = kmRodados.Text.ToString();
            var mediaC = Double.Parse(kmR) / Double.Parse(litrosA);
            var valorGasto = Double.Parse(litrosA) * Double.Parse(valorG);
            DisplayAlert("Dados calculados", "Média " + mediaC
                + "\nGasto " + valorGasto, "OK");
			media.Text = "Média: " + mediaC;
            total.Text = "Total: " + valorGasto;
        }
	}
}