Summary
Projects each element of an observable sequence to an observable sequence by incorporating the element's index, invokes the result selector for the source element and each of the corresponding inner sequence's elements, and merges the results into one observable sequence.
Syntax
public static IObservable<TResult> ConcatMap<TSource, TCollection, TResult>(this IObservable<TSource> source, Func<TSource, int, IObservable<TCollection>> collectionSelector, Func<TSource, int, TCollection, int, TResult> resultSelector)
Type Parameters
Name |
Description |
TSource |
The type of the elements in the source sequence. |
TCollection |
The type of the elements in the projected intermediate sequences. |
TResult |
The type of the elements in the result sequence, obtained by using the selector to combine source sequence elements with their corresponding intermediate sequence elements. |
Parameters
Name |
Type |
Description |
source |
IObservable<TSource> |
An observable sequence of elements to project. |
collectionSelector |
Func<TSource, int, IObservable<TCollection>> |
A transform function to apply to each element; the second parameter of the function represents the index of the source element. |
resultSelector |
Func<TSource, int, TCollection, int, TResult> |
A transform function to apply to each element of the intermediate sequence; the second parameter of the function represents the index of the source element and the fourth parameter represents the index of the intermediate element. |
Return Value
Type |
Description |
IObservable<TResult> |
An observable sequence whose elements are the result of invoking the one-to-many transform function collectionSelector on each element of the input sequence and then mapping each of those sequence elements and their corresponding source element to a result element. |