ParallelEnumerable.Sum(Of TSource) Method (ParallelQuery(Of TSource), Func(Of TSource, Nullable(Of Int64)))
Computes in parallel the sum of the sequence of values that are obtained by invoking a transform function on each element of the input sequence.
Assembly: System.Core (in System.Core.dll)
'Declaration <ExtensionAttribute> _ Public Shared Function Sum(Of TSource) ( _ source As ParallelQuery(Of TSource), _ selector As Func(Of TSource, Nullable(Of Long)) _ ) As Nullable(Of Long)
The type of elements of source.
- Type: System.Linq.ParallelQuery(Of )
A sequence of values to calculate the sum of.
Usage NoteIn Visual Basic and C#, you can call this method as an instance method on any object of type ParallelQuery(Of ). When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).
The query was canceled with the token passed in through WithCancellation.
source or selector is a null reference (Nothing in Visual Basic).
The sum is larger than MaxValue. -or- One or more exceptions occurred during the evaluation of the query.