borepin/Borepin/Borepin/Page/TestPage.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="Borepin.Page.TestPage"
             xmlns:converters="clr-namespace:Borepin.Converter">
    <ContentPage.Resources>
        <ResourceDictionary>
            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
        </ResourceDictionary>
    </ContentPage.Resources>
    <ContentPage.Content>
        <StackLayout Padding="20">
            <StackLayout IsVisible="{Binding IsBusy}">
                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
            </StackLayout>
            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
                <Label Text="TestPage"/>
            </StackLayout>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>