Qbservable

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

Creates a lookup from 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 ToLookup(Of TSource, TKey) ( _
    source As IQbservable(Of TSource), _
    keySelector As Expression(Of Func(Of TSource, TKey)) _
) As IQbservable(Of ILookup(Of TKey, TSource))
'Usage
Dim source As IQbservable(Of TSource)
Dim keySelector As Expression(Of Func(Of TSource, TKey))
Dim returnValue As IQbservable(Of ILookup(Of TKey, TSource))

returnValue = source.ToLookup(keySelector)
public static IQbservable<ILookup<TKey, TSource>> ToLookup<TSource, TKey>(
    this IQbservable<TSource> source,
    Expression<Func<TSource, TKey>> keySelector
)
[ExtensionAttribute]
public:
generic<typename TSource, typename TKey>
static IQbservable<ILookup<TKey, TSource>^>^ ToLookup(
    IQbservable<TSource>^ source, 
    Expression<Func<TSource, TKey>^>^ keySelector
)
static member ToLookup : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> -> IQbservable<ILookup<'TKey, 'TSource>> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.

  • TKey
    The type of key.

Parameters

Return Value

Type: System.Reactive.Linq.IQbservable<ILookup<TKey, TSource>>
A lookup from a queryable observable sequence according to a specified key selector function.

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

ToLookup Overload

System.Reactive.Linq Namespace

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

Creates a lookup from a queryable observable sequence according to a specified key selector function, a comparer, and an element selector function.

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function ToLookup(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 ILookup(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 ILookup(Of TKey, TElement))

returnValue = source.ToLookup(keySelector, _
    elementSelector, comparer)
public static IQbservable<ILookup<TKey, TElement>> ToLookup<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<ILookup<TKey, TElement>^>^ ToLookup(
    IQbservable<TSource>^ source, 
    Expression<Func<TSource, TKey>^>^ keySelector, 
    Expression<Func<TSource, TElement>^>^ elementSelector, 
    IEqualityComparer<TKey>^ comparer
)
static member ToLookup : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> * 
        elementSelector:Expression<Func<'TSource, 'TElement>> * 
        comparer:IEqualityComparer<'TKey> -> IQbservable<ILookup<'TKey, 'TElement>> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.

  • TKey
    The type of key.

  • TElement
    The type of element.

Parameters

Return Value

Type: System.Reactive.Linq.IQbservable<ILookup<TKey, TElement>>
A lookup from a queryable observable sequence according to a specified key selector function, a comparer, and an element selector function.

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

ToLookup Overload

System.Reactive.Linq Namespace

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

Creates a lookup from a queryable observable sequence according to a specified key selector function, and an element selector function.

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function ToLookup(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 ILookup(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 ILookup(Of TKey, TElement))

returnValue = source.ToLookup(keySelector, _
    elementSelector)
public static IQbservable<ILookup<TKey, TElement>> ToLookup<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<ILookup<TKey, TElement>^>^ ToLookup(
    IQbservable<TSource>^ source, 
    Expression<Func<TSource, TKey>^>^ keySelector, 
    Expression<Func<TSource, TElement>^>^ elementSelector
)
static member ToLookup : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> * 
        elementSelector:Expression<Func<'TSource, 'TElement>> -> IQbservable<ILookup<'TKey, 'TElement>> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.

  • TKey
    The type of key.

  • TElement
    The type of element.

Parameters

Return Value

Type: System.Reactive.Linq.IQbservable<ILookup<TKey, TElement>>
A lookup from a queryable observable sequence according to a specified key selector function, and an element selector function.

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

ToLookup Overload

System.Reactive.Linq Namespace

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

Creates a lookup from a queryable observable sequence according to a specified key selector function, and a comparer.

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function ToLookup(Of TSource, TKey) ( _
    source As IQbservable(Of TSource), _
    keySelector As Expression(Of Func(Of TSource, TKey)), _
    comparer As IEqualityComparer(Of TKey) _
) As IQbservable(Of ILookup(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 ILookup(Of TKey, TSource))

returnValue = source.ToLookup(keySelector, _
    comparer)
public static IQbservable<ILookup<TKey, TSource>> ToLookup<TSource, TKey>(
    this IQbservable<TSource> source,
    Expression<Func<TSource, TKey>> keySelector,
    IEqualityComparer<TKey> comparer
)
[ExtensionAttribute]
public:
generic<typename TSource, typename TKey>
static IQbservable<ILookup<TKey, TSource>^>^ ToLookup(
    IQbservable<TSource>^ source, 
    Expression<Func<TSource, TKey>^>^ keySelector, 
    IEqualityComparer<TKey>^ comparer
)
static member ToLookup : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> * 
        comparer:IEqualityComparer<'TKey> -> IQbservable<ILookup<'TKey, 'TSource>> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.

  • TKey
    The type of key.

Parameters

Return Value

Type: System.Reactive.Linq.IQbservable<ILookup<TKey, TSource>>
A lookup from a queryable observable sequence according to a specified key selector function, and a comparer.

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

ToLookup Overload

System.Reactive.Linq Namespace