Observable.Where<TSource> Method (IObservable<TSource>, Func<TSource, Int32, Boolean>)

Filters the elements of an observable sequence based on a predicate by incorporating the element's index.

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

public static IObservable<TSource> Where<TSource>(
	this IObservable<TSource> source,
	Func<TSource, int, bool> predicate

Type Parameters


The type source.


Type: System.IObservable<TSource>
An observable sequence whose elements to filter.
Type: System.Func<TSource, Int32, Boolean>
A function to test each source element for a condition; the second parameter of the function represents the index of the source element.

Return Value

Type: System.IObservable<TSource>
An observable sequence that contains elements from the input sequence that satisfy the condition.

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 https://msdn.microsoft.com/en-us/library/bb384936.aspx or https://msdn.microsoft.com/en-us/library/bb383977.aspx.