A generic equality comparer that takes a property expression or a comparison Func 

public class GenericComparer<T> : IEqualityComparer<T> where T : class
        {
            private readonly Func<T, T, bool> comparerExpression;
            private readonly string propertyName;
 
            public GenericComparer(Func<T, T, bool> comparerExpression)
            {
                this.comparerExpression = comparerExpression;
            }
 
            public GenericComparer(Expression<Func<T, object>> propertyExpression)
            {
                propertyName = (propertyExpression.Body is UnaryExpression ? (MemberExpression)((UnaryExpression)propertyExpression.Body).Operand : (MemberExpression)propertyExpression.Body).Member.Name;
            }
 
            public bool Equals(T x, T y)
            {
                return comparerExpression == null ? x.GetType().GetProperty(propertyName).GetValue(x, null).Equals(y.GetType().GetProperty(propertyName).GetValue(y, null)) : comparerExpression.Invoke(x, y);
            }
 
            public int GetHashCode(T obj)
            {
                return obj.ToString().GetHashCode();
            }
        }