Xamarin Forms MasterDetalPage XAML

MasterDetailPageDemo.xaml

<MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"       
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
    xmlns:view="clr-namespace:DemoApp.Views;assembly=DemoApp"
    x:Class="DemoApp.Views.RootPage" Title="MasterDetailPage Demo">
    <MasterDetailPage.Master>
        <view:MainMenu />
    </MasterDetailPage.Master>
    <MasterDetailPage.Detail>
        <view:HomePage />
    </MasterDetailPage.Detail>
</MasterDetailPage>

<!-- Menu -->

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
                       xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                       x:Class="DemoApp.Views.MainMenu">
    <Label Text="Hello World" VerticalOptions="Center" HorizontalOptions="Center" />
</ContentPage>

<!-- Detail -->

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
                       xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                       x:Class="DemoApp.Views.HomePage">
    <Label Text="Hello World" VerticalOptions="Center" HorizontalOptions="Center" />
</ContentPage>