Qbservable.ElementAtOrDefault<TSource> Method

Returns the element at a specified index in a sequence or a default value if the index is out of range.

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function ElementAtOrDefault(Of TSource) ( _
    source As IQbservable(Of TSource), _
    index As Integer _
) As IQbservable(Of TSource)
'Usage
Dim source As IQbservable(Of TSource)
Dim index As Integer
Dim returnValue As IQbservable(Of TSource)

returnValue = source.ElementAtOrDefault(index)
public static IQbservable<TSource> ElementAtOrDefault<TSource>(
    this IQbservable<TSource> source,
    int index
)
[ExtensionAttribute]
public:
generic<typename TSource>
static IQbservable<TSource>^ ElementAtOrDefault(
    IQbservable<TSource>^ source, 
    int index
)
static member ElementAtOrDefault : 
        source:IQbservable<'TSource> * 
        index:int -> IQbservable<'TSource> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.

Parameters

  • index
    Type: System.Int32
    The zero-based index of the element to retrieve.

Return Value

Type: System.Reactive.Linq.IQbservable<TSource>
A queryable observable sequence that produces the element at the specified position in the source sequence or a default value if the index is outside the bounds of the source sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IQbservable<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see or .

See Also

Reference

Qbservable Class

System.Reactive.Linq Namespace