Observable.ToDictionary<TSource, TKey, TElement> Method (IObservable<TSource>, Func<TSource, TKey>, Func<TSource, TElement>)

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

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function ToDictionary(Of TSource, TKey, TElement) ( _
    source As IObservable(Of TSource), _
    keySelector As Func(Of TSource, TKey), _
    elementSelector As Func(Of TSource, TElement) _
) As IObservable(Of IDictionary(Of TKey, TElement))
'Usage
Dim source As IObservable(Of TSource)
Dim keySelector As Func(Of TSource, TKey)
Dim elementSelector As Func(Of TSource, TElement)
Dim returnValue As IObservable(Of IDictionary(Of TKey, TElement))

returnValue = source.ToDictionary(keySelector, _
    elementSelector)
public static IObservable<IDictionary<TKey, TElement>> ToDictionary<TSource, TKey, TElement>(
    this IObservable<TSource> source,
    Func<TSource, TKey> keySelector,
    Func<TSource, TElement> elementSelector
)
[ExtensionAttribute]
public:
generic<typename TSource, typename TKey, typename TElement>
static IObservable<IDictionary<TKey, TElement>^>^ ToDictionary(
    IObservable<TSource>^ source, 
    Func<TSource, TKey>^ keySelector, 
    Func<TSource, TElement>^ elementSelector
)
static member ToDictionary : 
        source:IObservable<'TSource> * 
        keySelector:Func<'TSource, 'TKey> * 
        elementSelector:Func<'TSource, 'TElement> -> IObservable<IDictionary<'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

  • source
    Type: System.IObservable<TSource>
    An observable sequence to create a dictionary for.
  • keySelector
    Type: System.Func<TSource, TKey>
    A function to extract a key from each element.
  • elementSelector
    Type: System.Func<TSource, TElement>
    A transform function to produce a result element value from each element.

Return Value

Type: System.IObservable<IDictionary<TKey, TElement>>
The dictionary from an 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 IObservable<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see or .

See Also

Reference

Observable Class

ToDictionary Overload

System.Reactive.Linq Namespace