prs/prs.mobile.new/PRS.Mobile/CustomControls/StringList.xaml

<?xml version="1.0" encoding="UTF-8"?>
<ContentView xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="PRS.Mobile.StringList">
    <ContentView.Content>
        <Grid x:Name="_grid" ColumnSpacing="0">
            
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            
            <ImageButton 
                x:Name="_addbutton"
                Grid.Row="0" 
                Grid.Column="1" 
                Source="plus"
                HeightRequest="40"
                WidthRequest="40"
                VerticalOptions="Center" 
                Clicked="AddBtn_Clicked"/>
            
        </Grid>
    </ContentView.Content>
</ContentView>