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](IGroupedObservable/IGroupedObservable(TKey,)<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 .

See Also

Reference

Qbservable Class

GroupBy Overload

System.Reactive.Linq Namespace

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](IGroupedObservable/IGroupedObservable(TKey,)<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

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

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

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)), _
    comparer As IEqualityComparer(Of 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 comparer As IEqualityComparer(Of TKey)
Dim returnValue As IQbservable(Of IGroupedObservable(Of TKey, TSource))

returnValue = source.GroupBy(keySelector, _
    comparer)

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

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

static member GroupBy : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> * 
        comparer:IEqualityComparer<'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.

• comparer
  Type: System.Collections.Generic.IEqualityComparer<TKey>
  An equality comparer to compare keys with.

Return Value

Type: System.Reactive.Linq.IQbservable<[IGroupedObservable](IGroupedObservable/IGroupedObservable(TKey,)<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

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

Groups the elements of a queryable 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.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)), _
    comparer As IEqualityComparer(Of TKey) _
) 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 comparer As IEqualityComparer(Of TKey)
Dim returnValue As IQbservable(Of IGroupedObservable(Of TKey, TElement))

returnValue = source.GroupBy(keySelector, _
    elementSelector, comparer)

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

[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, 
    IEqualityComparer<TKey>^ comparer
)

static member GroupBy : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> * 
        elementSelector:Expression<Func<'TSource, 'TElement>> * 
        comparer:IEqualityComparer<'TKey> -> 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.

• comparer
  Type: System.Collections.Generic.IEqualityComparer<TKey>
  An equality comparer to compare keys with.

Return Value

Type: System.Reactive.Linq.IQbservable<[IGroupedObservable](IGroupedObservable/IGroupedObservable(TKey,)<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 .

See Also

Reference

Qbservable Class

GroupBy Overload

System.Reactive.Linq Namespace