Qbservable.GroupBy<TSource, TKey, TElement> Method (IQbservable<TSource>, Expression<Func<TSource, TKey>>, Expression<Func<TSource, TElement>>)
Groups the elements of a queryable observable sequence and selects the resulting elements by using a specified function.
Namespace: System.Reactive.Linq
Assembly: System.Reactive.Providers (in System.Reactive.Providers.dll)
Syntax
'Declaration
<ExtensionAttribute> _
Public Shared Function GroupBy(Of TSource, TKey, TElement) ( _
source As IQbservable(Of TSource), _
keySelector As Expression(Of Func(Of TSource, TKey)), _
elementSelector As Expression(Of Func(Of TSource, TElement)) _
) As IQbservable(Of IGroupedObservable(Of TKey, TElement))
'Usage
Dim source As IQbservable(Of TSource)
Dim keySelector As Expression(Of Func(Of TSource, TKey))
Dim elementSelector As Expression(Of Func(Of TSource, TElement))
Dim returnValue As IQbservable(Of IGroupedObservable(Of TKey, TElement))
returnValue = source.GroupBy(keySelector, _
elementSelector)
public static IQbservable<IGroupedObservable<TKey, TElement>> GroupBy<TSource, TKey, TElement>(
this IQbservable<TSource> source,
Expression<Func<TSource, TKey>> keySelector,
Expression<Func<TSource, TElement>> elementSelector
)
[ExtensionAttribute]
public:
generic<typename TSource, typename TKey, typename TElement>
static IQbservable<IGroupedObservable<TKey, TElement>^>^ GroupBy(
IQbservable<TSource>^ source,
Expression<Func<TSource, TKey>^>^ keySelector,
Expression<Func<TSource, TElement>^>^ elementSelector
)
static member GroupBy :
source:IQbservable<'TSource> *
keySelector:Expression<Func<'TSource, 'TKey>> *
elementSelector:Expression<Func<'TSource, 'TElement>> -> IQbservable<IGroupedObservable<'TKey, 'TElement>>
JScript does not support generic types and methods.
Type Parameters
- TSource
The type source.
- TKey
The type key.
- TElement
The type element.
Parameters
- source
Type: System.Reactive.Linq.IQbservable<TSource>
A queryable observable sequence whose elements to group.
- keySelector
Type: System.Linq.Expressions.Expression<Func<TSource, TKey>>
A function to extract the key for each element.
- elementSelector
Type: System.Linq.Expressions.Expression<Func<TSource, TElement>>
A function to map each source element to an element in an observable group.
Return Value
Type: System.Reactive.Linq.IQbservable<IGroupedObservable<TKey, TElement>>
A sequence of queryable observable groups, each of which corresponds to a unique key value, containing all elements that share that same key value.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IQbservable<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see or .