Summary
Projects each element of an observable sequence to a task by incorporating the element's index with cancellation support, invokes the result selector for the source element and the task result, and merges the results into one observable sequence.
Syntax
public static IObservable<TResult> ConcatMap<TSource, TTaskResult, TResult>(this IObservable<TSource> source, Func<TSource, int, CancellationToken, Task<TTaskResult>> taskSelector, Func<TSource, int, TTaskResult, TResult> resultSelector)
Type Parameters
Name |
Description |
TSource |
The type of the elements in the source sequence. |
TTaskResult |
The type of the results produced by the projected intermediate tasks. |
TResult |
The type of the elements in the result sequence, obtained by using the selector to combine source sequence elements with their corresponding intermediate task results. |
Parameters
Name |
Type |
Description |
source |
IObservable<TSource> |
An observable sequence of elements to project. |
taskSelector |
Func<TSource, int, CancellationToken, Task<TTaskResult>> |
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, TTaskResult, 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. |
Return Value
Type |
Description |
IObservable<TResult> |
An observable sequence whose elements are the result of obtaining a task for each element of the input sequence and then mapping the task's result and its corresponding source element to a result element. |