XamarinWhatsApp: PaginaMensaje.xaml

PaginaMensaje.xaml

<?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="XamarinWhatsApp.Paginas.PaginaMensaje" Title="Xamarin y WhatsApp">

    <ContentPage.Resources>
        <ResourceDictionary>
            <OnPlatform 
                x:Key="FontAwesome5" 
                x:TypeArguments="x:String" 
                Android="fa-regular-400.ttf#Font Awesome 5 Free Regular" 
                iOS="Font Awesome 5 Free" 
                WinPhone="Assets/fa-regular-400.ttf#Font Awesome 5 Free" />

            <Style TargetType="Label" x:Key="labelStyle">
                <Setter Property="FontSize" Value="Large"/>
                <Setter Property="FontAttributes" Value="Bold"/>
                <Setter Property="VerticalTextAlignment" Value="Center"/>
                <Setter Property="Margin" Value="5"/>
                <Setter Property="FontFamily" Value="{DynamicResource FontAwesome5}"/>
            </Style>

            <Style TargetType="Entry" x:Key="entryStyle">
                <Setter Property="TextColor" Value="Black"/>
                <Setter Property="FontSize" Value="Medium"/>
                <Setter Property="VerticalOptions" Value="End"/>
                <Setter Property="Margin" Value="5"/>
            </Style>

            <Style TargetType="Button" x:Key="buttonStyle">
                <Setter Property="FontSize" Value="Large"/>
                <Setter Property="BackgroundColor" Value="Transparent"/>
                <Setter Property="VerticalOptions" Value="Center"/>
                <Setter Property="Margin" Value="5"/>
                <Setter Property="FontFamily" Value="{DynamicResource FontAwesome5}"/>
            </Style>
        </ResourceDictionary>
    </ContentPage.Resources>
    <ContentPage.Content>
        <Grid BackgroundColor="White">
            <Grid.RowDefinitions>
                <RowDefinition Height="20"/>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="*"/>
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="20"/>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>

            <Label Style="{StaticResource labelStyle}" Grid.Row="1" Grid.Column="1" Text="&#xf580;" TextColor="Orange"/>
            <Entry Style="{StaticResource entryStyle}" Grid.Row="1" Grid.Column="2" x:Name="txtFrom" Placeholder="De: " Keyboard="Telephone"/>

            <Label Style="{StaticResource labelStyle}" Grid.Row="2" Grid.Column="1" Text="&#xf007;" TextColor="Blue"/>
            <Entry Style="{StaticResource entryStyle}" Grid.Row="2" Grid.Column="2" x:Name="txtTo" Placeholder="Para: " Keyboard="Telephone"/>

            <Label Style="{StaticResource labelStyle}" Grid.Row="3" Grid.Column="1" Text="&#xf075;" TextColor="Gray"/>
            <Entry Style="{StaticResource entryStyle}" Grid.Row="3" Grid.Column="2" x:Name="txtBody" Placeholder="Mensaje" Keyboard="Chat"/>
            <Button Style="{StaticResource buttonStyle}" Grid.Row="3" Grid.Column="3" x:Name="btnEnviar" Text="&#xf1d8;" TextColor="Green" Clicked="btnEnviar_Clicked"/>

            <ScrollView Grid.Row="4" Grid.Column="2" Grid.ColumnSpan="2">
                <ListView x:Name="lsvMensajes" 
                          VerticalOptions="FillAndExpand"
                          HasUnevenRows="True"
                          Margin="3">
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <StackLayout Padding="5">
                                    <Label Text="{Binding To}" TextColor="Blue" FontSize="Small" Margin="2"/>
                                    <Label Text="{Binding Body}" TextColor="Black" FontSize="Small" Margin="2"/>
                                    <Label Text="{Binding Sid}" TextColor="Gray" FontSize="Small" Margin="2"/>
                                </StackLayout>
                            </ViewCell>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>
            </ScrollView>
        </Grid>
    </ContentPage.Content>
</ContentPage>