Observable::GroupBy<TSource, TKey, TElement> Method (IObservable<TSource>, Func<TSource, TKey>, Func<TSource, TElement>, IEqualityComparer<TKey>)
Groups the elements of an observable sequence according to a specified key selector function and comparer and selects the resulting elements by using a specified function.
Namespace: System.Reactive.Linq
Assembly: System.Reactive (in System.Reactive.dll)
[ExtensionAttribute] public: generic<typename TSource, typename TKey, typename TElement> static IObservable<IGroupedObservable<TKey, TElement>^>^ GroupBy( IObservable<TSource>^ source, Func<TSource, TKey>^ keySelector, Func<TSource, TElement>^ elementSelector, IEqualityComparer<TKey>^ comparer )
Type Parameters
- TSource
The type source.
- TKey
The type key.
- TElement
The type element.
Parameters
- source
- Type: System::IObservable<TSource>
An observable sequence whose elements to group.
- keySelector
- Type: System::Func<TSource, TKey>
A function to extract the key for each element.
- elementSelector
- Type: System::Func<TSource, TElement>
A function to map each source element to an element in an observable group.
- comparer
- Type: System.Collections.Generic::IEqualityComparer<TKey>
An equality comparer to compare keys with.
Return Value
Type: System::IObservable<IGroupedObservable<TKey, TElement>>A sequence of observable groups, each of which corresponds to a unique key value, containing all elements that share that same key value.
