Observable.Scan(Of TSource, TAccumulate) Method (IObservable(Of TSource), TAccumulate, Func(Of TAccumulate, TSource, TAccumulate))

Applies an accumulator function over an observable sequence and returns each intermediate result with the specified source, seed and accumulator.

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

<ExtensionAttribute> _
Public Shared Function Scan(Of TSource, TAccumulate) ( _
	source As IObservable(Of TSource), _
	seed As TAccumulate, _
	accumulator As Func(Of TAccumulate, TSource, TAccumulate) _
) As IObservable(Of TAccumulate)
Dim source As IObservable(Of TSource)
Dim seed As TAccumulate
Dim accumulator As Func(Of TAccumulate, TSource, TAccumulate)
Dim returnValue As IObservable(Of TAccumulate)

returnValue = source.Scan(seed, accumulator)

Type Parameters


The type of source.


The type of accumulator.


Type: System.IObservable(Of TSource)
An observable sequence to accumulate over.
Type: TAccumulate
The initial accumulator value.
Type: System.Func(Of TAccumulate, TSource, TAccumulate)
An accumulator function to be invoked on each element.

Return Value

Type: System.IObservable(Of TAccumulate)
An observable sequence containing the accumulated values.

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 https://msdn.microsoft.com/en-us/library/bb384936(v=vs.103).aspx or https://msdn.microsoft.com/en-us/library/bb383977(v=vs.103).aspx.