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Observable.Contains<TSource> Method (IObservable<TSource>, TSource, IEqualityComparer<TSource>)

Determines whether an observable sequence contains a specified element by using a specified System.Collections.Generic.IEqualityComparer&lt;T&gt;.

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


<ExtensionAttribute> _
Public Shared Function Contains(Of TSource) ( _
    source As IObservable(Of TSource), _
    value As TSource, _
    comparer As IEqualityComparer(Of TSource) _
) As IObservable(Of Boolean)
Dim source As IObservable(Of TSource)
Dim value As TSource
Dim comparer As IEqualityComparer(Of TSource)
Dim returnValue As IObservable(Of Boolean)

returnValue = source.Contains(value, _
public static IObservable<bool> Contains<TSource>(
    this IObservable<TSource> source,
    TSource value,
    IEqualityComparer<TSource> comparer
generic<typename TSource>
static IObservable<bool>^ Contains(
    IObservable<TSource>^ source, 
    TSource value, 
    IEqualityComparer<TSource>^ comparer
static member Contains : 
        source:IObservable<'TSource> * 
        value:'TSource * 
        comparer:IEqualityComparer<'TSource> -> IObservable<bool> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.


  • source
    Type: System.IObservable<TSource>
    An observable sequence in which to locate a value.
  • value
    Type: TSource
    The value to locate a sequence.

Return Value

Type: System.IObservable<Boolean>
True if an observable sequence contains a specified element by using a specified System.Collections.Generic.IEqualityComparer&lt;T&gt; otherwise, false.

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


Observable Class

Contains Overload

System.Reactive.Linq Namespace