Creating a simplified version of ConstraintExpression with Type=RelativeToView

ToViewExtension.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xamarin.Forms;
using Xamarin.Forms.Internals;
using Xamarin.Forms.Xaml;

namespace Playground.Helpers
{
    [ContentProperty(nameof(Value))]
    public class ToViewExtension : IMarkupExtension<Constraint>
    {
        public string Value { get; set; }

        public Constraint ProvideValue(IServiceProvider serviceProvider)
        {
            if (Value is null)
                return null;
            var values = Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
            if (values.Length != 4)
                return null;
            // Removing white spaces
            for (int i = 0; i < values.Length; i++)
                values[i] = values[i].Trim();
            // Getting values to define Constraint
            var elementName = values[0];
            var property = values[1];
            if (!double.TryParse(values[2], out double constant))
                return null;
            if (!double.TryParse(values[3], out double factor))
                return null;
            //
            IReferenceProvider service1 = serviceProvider.GetService<IReferenceProvider>();
            View byName;
            if (service1 != null)
            {
                byName = (View)service1.FindByName(elementName);
            }
            else
            {
                IProvideValueTarget service2 = serviceProvider.GetService<IProvideValueTarget>();
                if (service2 == null || !(service2.TargetObject is INameScope))
                    return (Constraint)null;
                byName = ((INameScope) service2.TargetObject).FindByName(elementName) as View;
            }
            var pi = typeof(RelativeLayout).GetProperties()
                .FirstOrDefault(a => a.Name == property.ToString() && a.CanRead);
            return Constraint.RelativeToView(byName, (p, v) => (double)pi.GetValue(v) * factor + constant);
        }

        object IMarkupExtension.ProvideValue(IServiceProvider serviceProvider)
        {
            return ProvideValue(serviceProvider);
        }
    }
}