CancellationToken and SQL LogFile

where · Originally posted by mgood

   Hello,
I don't know how CancellationToken works, so I'm doing some tests and I'm trying to cancel the execution of my queries. Actually, I have a search component that make searches while the user is typing and I wish my component cancel the previous query (if not finished yet) when the user type a new key. For example, if the user type quickly "Anna", the application should search "Anna" and not the partials "A", "An", "Ann". 

In the KeyUp event, I call this method:
private async void Search(string textSearch)
{
	try
	{
		if (!string.IsNullOrWhiteSpace(textSearch))
		{
			foreach (var item in _cancellationTokenSourceList)
				item.Cancel();
			_cancellationTokenSourceList.Clear();

			CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
			_cancellationTokenSourceList.Add(cancellationTokenSource);

			var predicate = PredicateBuilder.Make(typeof(T), _fieldName, FilterOperator.Contains, textSearch);
			var result = await _unitOfWork.Entities.FindAsync(f => f.Where(predicate).OrderBySelector(new SortSelector(_fieldName)).Take(PageSize), cancellationTokenSource.Token);
			ItemsSource = new BindableCollection<T>(result);

			_currentComponent.ShowPopup();
		}
		else
		{
			ItemsSource.Clear();
			_currentComponent.ClosePopup();
		}
	}
	catch (System.Exception)
	{
		//throw;
	}
}

I don't know if it's working or not, because when I take a look in the log file I can see a bunch of the same query with differents where clauses. 
Sometimes I have exactly the sequence that the user typed:
1. WHERE (LOWER("Extent1"."Name") LIKE 'A%')
2. WHERE (LOWER("Extent1"."Name") LIKE 'An%')
3. WHERE (LOWER("Extent1"."Name") LIKE 'Ann%')
4. WHERE (LOWER("Extent1"."Name") LIKE 'Anna%')

Sometimes a strange sequence and repetead queries:
1. WHERE (LOWER("Extent1"."Name") LIKE 'An%')
2. WHERE (LOWER("Extent1"."Name") LIKE 'Ann%')
3. WHERE (LOWER("Extent1"."Name") LIKE 'Ann%')
4. WHERE (LOWER("Extent1"."Name") LIKE 'Anna%')

I don't know why this behavior happens and I don't know if the cancellation is happening or not because anything is mentioned in the log.

Regards.