XPQueryExtensions.SumAsync<T>(IQueryable<T>, Expression<Func<T, Nullable<Double>>>, CancellationToken) Method

Asynchronously calculates a sum of objects’ specific nullable Double fields for a query. Uses a lambda expression to obtain values.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v21.2.dll

Declaration

C#

public static Task<double?> SumAsync<T>(
    this IQueryable<T> query,
    Expression<Func<T, double?>> selector,
    CancellationToken cancellationToken = default(CancellationToken)
)

VB.NET

<ExtensionAttribute>
Public Shared Function SumAsync(Of T)(
    query As IQueryable(Of T),
    selector As Expression(Of Func(Of T, Double?)),
    cancellationToken As CancellationToken = Nothing
) As Task(Of Double?)

Parameters

Name	Type	Description
query	IQueryable<T>	An XPQuery<T> object that specifies a persistent object selection.
selector	Expression<Func<T, Nullable<Double>>>	A lambda expression that gets a value from a persistent object.

Optional Parameters

Name	Type	Default	Description
cancellationToken	CancellationToken	null	A CancellationToken object that delivers a cancellation notice to the running operation.

Type Parameters

Name
T

Returns

Type	Description
Task<Nullable<Double>>	A Task that returns a sum of objects’ specific nullable Double fields for a query.