void FilterItems(string filter)
{
var filteredItems = source.Where(Patient => Patient.Evaluation.ToLower().Contains(filter.ToLower())).ToList();
foreach (var Patient in source)
{
if (!filteredItems.Contains(Patient))
{
Evaluations.Remove(Patient);
}
else
{
if (!Evaluations.Contains(Patient))
{
Evaluations.Add(Patient);
}
}
}
}