public void PerformFiltering()
{
if (_filter == null)
{
_filter = "";
}
_allCities = DataRepo.AllCities;
//Lower-case and trim string
var lowerCaseFilter = Filter.ToLowerInvariant().Trim();
//Use LINQ query to get all personmodel names that match filter text, as a list
var result = _allCities.Where(tf => tf.Name.ToLowerInvariant().Contains(lowerCaseFilter)).ToList();
var resultCount = result.Count;
var toRemove = new List <CityModel>();
if (Cities.Count > 0)
{
toRemove = Cities.Except(result).ToList();
}
//Loop to remove items that fail filter
foreach (var x in toRemove)
{
Cities.Remove(x);
}
// Add back in correct order.
for (int i = 0; i < resultCount; i++)
{
var resultItem = result[i];
if (i + 1 > Cities.Count || !Cities[i].Equals(resultItem))
{
Cities.Insert(i, resultItem);
}
}
}