SelectMany Method

SelectMany<TSource, TCollection, TResult>(IIndexedSource<TSource>, Expression<Func<TSource, IEnumerable<TCollection>>>, Expression<Func<TSource, TCollection, TResult>>)

Projects each element of a collection to a sequence of collections, flattens the resulting collections into one collection, and invokes a result selector function on each element therein.

Declaration

public static IIndexedSource<TResult> SelectMany<TSource, TCollection, TResult>(this IIndexedSource<TSource> source, Expression<Func<TSource, IEnumerable<TCollection>>> collectionSelector, Expression<Func<TSource, TCollection, TResult>> resultSelector)

Public Shared Function SelectMany(Of TSource, TCollection, TResult)(source As IIndexedSource(Of TSource), collectionSelector As Expression(Of Func(Of TSource, IEnumerable(Of TCollection))), resultSelector As Expression(Of Func(Of TSource, TCollection, TResult))) As IIndexedSource(Of TResult)

Parameters

Type	Name	Description
IIndexedSource<TSource>	source	A collection of values to project.
Expression<Func<TSource, IEnumerable<TCollection>>>	collectionSelector	A transform function to apply to each element of the input collection.
Expression<Func<TSource, TCollection, TResult>>	resultSelector	A transform function to apply to each element of the intermediate sequence.

Returns

Type	Description
IIndexedSource<TResult>	An IIndexedSource<TResult> whose elements are the result of invoking the one-to-many transform function collectionSelector on each element of source and then mapping each of those sequence elements and their corresponding source element to a result element.

Type Parameters

Name	Description
TSource	The type of the elements of source.
TCollection	The type of the intermediate elements collected by collectionSelector.
TResult	The type of the elements of the resulting collection.

SelectMany<TSource, TResult>(IIndexedSource<TSource>, Expression<Func<TSource, IEnumerable<TResult>>>)

Projects each element of a collection to a sequence of collections and flattens the resulting collections into one collection.

Declaration

public static IIndexedSource<TResult> SelectMany<TSource, TResult>(this IIndexedSource<TSource> source, Expression<Func<TSource, IEnumerable<TResult>>> selector)

Public Shared Function SelectMany(Of TSource, TResult)(source As IIndexedSource(Of TSource), selector As Expression(Of Func(Of TSource, IEnumerable(Of TResult)))) As IIndexedSource(Of TResult)

Parameters

Type	Name	Description
IIndexedSource<TSource>	source	A collection of values to project.
Expression<Func<TSource, IEnumerable<TResult>>>	selector	A transform function to apply to each element.

Returns

Type	Description
IIndexedSource<TResult>	An IIndexedSource<TResult> whose elements are the result of invoking the one-to-many transform function on each element of the source collection.

Type Parameters

Name	Description
TSource	The type of the elements of source.
TResult	The type of the elements of the sequence returned by selector.