private void AppendFilter(object sender, RoutedEventArgs e)
{
PatientDbContext patientDbContext = new PatientDbContext();
string val = txtValue.Text;
dataGrid.ItemsSource =
patientDbContext
.Patients
.Where(i =>
i.FirstName.Contains(val) ||
i.LastName.Contains(val) ||
i.PatientId.Contains(val) ||
i.Title.Contains(val) && (
i.Created >= dtFromDate.DisplayDate &&
i.Created < dtFromDate.DisplayDate
)).ToList();
patientDbContext.Dispose();
}