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

Syntax

'Declaration
<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))

'Usage
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)

public static IQbservable<IGroupedObservable<TKey, TSource>> GroupBy<TSource, TKey>(
    this IQbservable<TSource> source,
    Expression<Func<TSource, TKey>> keySelector
)

[ExtensionAttribute]
public:
generic<typename TSource, typename TKey>
static IQbservable<IGroupedObservable<TKey, TSource>^>^ GroupBy(
    IQbservable<TSource>^ source, 
    Expression<Func<TSource, TKey>^>^ keySelector
)

static member GroupBy : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> -> IQbservable<IGroupedObservable<'TKey, 'TSource>> 

JScript does not support generic types and methods.

Type Parameters

• TSource
  The type source.

• TKey
  The type key.

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.

Return Value

Type: System.Reactive.Linq.IQbservable<IGroupedObservable<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<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see or .

See Also

Reference

Qbservable Class

GroupBy Overload

System.Reactive.Linq Namespace