ToDictionary(TSource, TKey, TElement) Method (ParallelQuery(TSource), Func(TSource, TKey), Func(TSource, TElement), IEqualityComparer(TKey))

Task Parallel System.Threading

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Creates a Dictionary{TKey,TValue from a ParallelQuery{T} according to a specified key selector function, a comparer, and an element selector function.

Namespace: System.Linq
Assembly: System.Threading (in System.Threading.dll)

Syntax

Visual Basic (Declaration)
Public Shared Function ToDictionary(Of TSource, TKey, TElement) ( _ source As ParallelQuery(Of TSource), _ keySelector As Func(Of TSource, TKey), _ elementSelector As Func(Of TSource, TElement), _ comparer As IEqualityComparer(Of TKey) _ ) As Dictionary(Of TKey, TElement)

Visual Basic (Declaration)

Public Shared Function ToDictionary(Of TSource, TKey, TElement) ( _
	source As ParallelQuery(Of TSource), _
	keySelector As Func(Of TSource, TKey), _
	elementSelector As Func(Of TSource, TElement), _
	comparer As IEqualityComparer(Of TKey) _
) As Dictionary(Of TKey, TElement)

C#
public static Dictionary<TKey, TElement> ToDictionary<TSource, TKey, TElement>( ParallelQuery<TSource> source, Func<TSource, TKey> keySelector, Func<TSource, TElement> elementSelector, IEqualityComparer<TKey> comparer )

public static Dictionary<TKey, TElement> ToDictionary<TSource, TKey, TElement>(
	ParallelQuery<TSource> source,
	Func<TSource, TKey> keySelector,
	Func<TSource, TElement> elementSelector,
	IEqualityComparer<TKey> comparer
)

Parameters

source: Type: System.Linq..::.ParallelQuery<(Of <(TSource>)>)
A sequence to create a Dictionary<(Of <(TKey, TValue>)>) from.

keySelector: Type: System..::.Func<(Of <(TSource, TKey>)>)
A function to extract a key from each element.

elementSelector: Type: System..::.Func<(Of <(TSource, TElement>)>)
A transform function to produce a result element value from each element.

comparer: Type: System.Collections.Generic..::.IEqualityComparer<(Of <(TKey>)>)
An IEqualityComparer<(Of <(T>)>) to compare keys.

Type Parameters

TSource: The type of the elements of source.
TKey: The type of the key returned by keySelector.
TElement: The type of the value returned by elementSelector.

Return Value

A Dictionary<(Of <(TKey, TValue>)>) that contains values of type TElement selected from the input sequence

Exceptions

Exception	Condition
System..::.ArgumentNullException	source or keySelector or elementSelector is a null reference (Nothing in Visual Basic).
System..::.AggregateException	keySelector produces a key that is a null reference (Nothing in Visual Basic). -or- keySelector produces duplicate keys for two elements. -or- One or more exceptions occurred during the evaluation of the query.
System..::.OperationCanceledException	The query was canceled.