public void FilterCollection()
{
if (FilterValue == null || FilterValue.Equals(default(TInner)))
{
FilteredCollection.Clear();
return;
}
foreach (var item in UnfilteredCollection)
{
if (PassFilterDelegate(item, FilterValue))
{
if (!FilteredCollection.Contains(item))
{
FilteredCollection.Add(item);
}
}
else
{
if (FilteredCollection.Contains(item))
{
FilteredCollection.Remove(item);
}
}
}
}
private async void RunFilter()
{
_delay?.Cancel();
_delay = new CancellationTokenSource();
try
{
await Task.Delay(500, _delay.Token);
}
catch (TaskCanceledException)
{
// request was canceled, return;
return;
}
var currentText = _searchBox?.Text ?? string.Empty;
var sourceCollection = SourceCollection.Cast <FileContainer>().ToList();
if (string.IsNullOrWhiteSpace(currentText))
{
// When nothing is being filtered, we dont need to filter any thing.
FilteredCollection.Clear();
FilteredCollection.AddRange(sourceCollection, true);
}
else
{
// Remove any items in the filtered collection that are no longer available in the primary collection
var oldItems = (from x in FilteredCollection where !sourceCollection.Contains(x) select x).ToList();
oldItems.ForEach(x => FilteredCollection.Remove(x));
// look at existing filtered items and remove those that do not match the filter
oldItems = (from x in FilteredCollection where !DoesContainString(x, currentText) select x).ToList();
oldItems.ForEach(x => FilteredCollection.Remove(x));
// Look at the source colleciton and find out what needs to be in the filtered collection
var newItems = (from x in sourceCollection where DoesContainString(x, currentText) && !FilteredCollection.Contains(x) select x).ToList();
FilteredCollection.AddRange(newItems, true);
}
}