First(TSource) Method (IObservable(TSource))
Collapse the table of content
Expand the table of content

Observable.First(Of TSource) Method (IObservable(Of TSource))

Returns the first element of an observable sequence with a specified source.

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

<ExtensionAttribute> _
Public Shared Function First(Of TSource) ( _
	source As IObservable(Of TSource) _
) As TSource
Dim source As IObservable(Of TSource)
Dim returnValue As TSource

returnValue = source.First()

Type Parameters


The type of source.


Type: System.IObservable(Of TSource)
The source observable sequence.

Return Value

Type: TSource
The first element in the observable sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IObservable(Of TSource). When you use instance method syntax to call this method, omit the first parameter. For more information, see or
© 2016 Microsoft