Qbservable.DistinctUntilChanged<TSource, TKey> Method (IQbservable<TSource>, Expression<Func<TSource, TKey>>, IEqualityComparer<TKey>)
Returns a queryable observable sequence that contains only distinct contiguous elements according to the keySelector and the comparer.
Namespace: System.Reactive.Linq
Assembly: System.Reactive.Providers (in System.Reactive.Providers.dll)
Syntax
'Declaration
<ExtensionAttribute> _
Public Shared Function DistinctUntilChanged(Of TSource, TKey) ( _
source As IQbservable(Of TSource), _
keySelector As Expression(Of Func(Of TSource, TKey)), _
comparer As IEqualityComparer(Of TKey) _
) As IQbservable(Of TSource)
'Usage
Dim source As IQbservable(Of TSource)
Dim keySelector As Expression(Of Func(Of TSource, TKey))
Dim comparer As IEqualityComparer(Of TKey)
Dim returnValue As IQbservable(Of TSource)
returnValue = source.DistinctUntilChanged(keySelector, _
comparer)
public static IQbservable<TSource> DistinctUntilChanged<TSource, TKey>(
this IQbservable<TSource> source,
Expression<Func<TSource, TKey>> keySelector,
IEqualityComparer<TKey> comparer
)
[ExtensionAttribute]
public:
generic<typename TSource, typename TKey>
static IQbservable<TSource>^ DistinctUntilChanged(
IQbservable<TSource>^ source,
Expression<Func<TSource, TKey>^>^ keySelector,
IEqualityComparer<TKey>^ comparer
)
static member DistinctUntilChanged :
source:IQbservable<'TSource> *
keySelector:Expression<Func<'TSource, 'TKey>> *
comparer:IEqualityComparer<'TKey> -> IQbservable<'TSource>
JScript does not support generic types and methods.
Type Parameters
- TSource
The type of source.
- TKey
The type of key.
Parameters
- source
Type: System.Reactive.Linq.IQbservable<TSource>
A queryable observable sequence to retain distinct contiguous elements for, based on a computed key value.
- keySelector
Type: System.Linq.Expressions.Expression<Func<TSource, TKey>>
A function to compute the comparison key for each element.
- comparer
Type: System.Collections.Generic.IEqualityComparer<TKey>
The equality comparer for computed key values.
Return Value
Type: System.Reactive.Linq.IQbservable<TSource>
A queryable observable sequence only containing the distinct contiguous elements, based on a computed key value, from 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 .