Custom font for iOS and Android in XAML

CustomFontsSamplePage.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"
             xmlns:local="clr-namespace:CustomFontsSample"
             x:Class="CustomFontsSample.CustomFontsSamplePage"
             Title="Custom Fonts">
    
    <Label Text="Welcome to Xamarin Forms!" VerticalOptions="Center" HorizontalOptions="Center">
        <Label.FontFamily>
            <OnPlatform x:TypeArguments="x:String">
                <On Platform="iOS" Value="ComicSansMS" />
                <On Platform="Android" Value="ComicSaaaans.ttf#ComicSansMS" />
            </OnPlatform>
        </Label.FontFamily>
    </Label>
</ContentPage>