Qbservable.GroupBy(Of TSource, TKey) Method (IQbservable(Of TSource), Expression(Of Func(Of TSource, TKey)))

Groups the elements of a queryable observable sequence according to a specified key selector function.

Namespace:  System.Reactive.Linq
Assembly:  System.Reactive.Providers (in System.Reactive.Providers.dll)

<ExtensionAttribute> _
Public Shared Function GroupBy(Of TSource, TKey) ( _
	source As IQbservable(Of TSource), _
	keySelector As Expression(Of Func(Of TSource, TKey)) _
) As IQbservable(Of IGroupedObservable(Of TKey, TSource))
Dim source As IQbservable(Of TSource)
Dim keySelector As Expression(Of Func(Of TSource, TKey))
Dim returnValue As IQbservable(Of IGroupedObservable(Of TKey, TSource))

returnValue = source.GroupBy(keySelector)

Type Parameters


The type source.


The type key.


Type: System.Reactive.Linq.IQbservable(Of TSource)
A queryable observable sequence whose elements to group.
Type: System.Linq.Expressions.Expression(Of Func(Of TSource, TKey))
A function to extract the key for each element.

Return Value

Type: System.Reactive.Linq.IQbservable(Of IGroupedObservable(Of TKey, TSource))
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(Of TSource). When you use instance method syntax to call this method, omit the first parameter. For more information, see https://msdn.microsoft.com/en-us/library/bb384936(v=vs.103).aspx or https://msdn.microsoft.com/en-us/library/bb383977(v=vs.103).aspx.