Observable.TakeWhile(TSource) Method (IObservable(TSource), Func(TSource, Int32, Boolean))

Returns values from an observable sequence as long as a specified condition is true, and then skips the remaining values.

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

static member TakeWhile : 
        source:IObservable<'TSource> * 
        predicate:Func<'TSource, int, bool> -> IObservable<'TSource> 

Type Parameters


The type source.


Type: System.IObservable(TSource)
A sequence to return elements from.
Type: System.Func(TSource, Int32, Boolean)
True to the function to test each element for a condition; the second parameter of the function represents the index of the source element; otherwise, false.

Return Value

Type: System.IObservable(TSource)
An observable sequence that contains the elements from the input sequence that occur before the element at which the test no longer passes.

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