Qbservable.GroupByUntil(TSource, TKey, TDuration) Method (IQbservable(TSource), Expression(Func(TSource, TKey)), Expression(Func(IGroupedObservable(TKey, TSource), IObservable(TDuration))))

Groups the elements of a queryable observable sequence according to a specified key selector function.

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

static member GroupByUntil : 
        source:IQbservable<'TSource> * 
        keySelector:Expression<Func<'TSource, 'TKey>> * 
        durationSelector:Expression<Func<IGroupedObservable<'TKey, 'TSource>, IObservable<'TDuration>>> -> IQbservable<IGroupedObservable<'TKey, 'TSource>> 

Type Parameters


The type source.


The type key.


The type duration.


Type: System.Reactive.Linq.IQbservable(TSource)
A queryable observable sequence whose elements to group.
Type: System.Linq.Expressions.Expression(Func(TSource, TKey))
A function to extract the key for each element.
Type: System.Linq.Expressions.Expression(Func(IGroupedObservable(TKey, TSource), IObservable(TDuration)))
A function to signal the expiration of a group.

Return Value

Type: System.Reactive.Linq.IQbservable(IGroupedObservable(TKey, TSource))
A sequence of queryable observable groups, each of which corresponds to a unique key value, containing all elements that share that same key value.

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 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.