XPQueryExtensions.SumAsync<T>(IQueryable<T>, Expression<Func<T, Nullable<Int64>>>, CancellationToken) Method

Asynchronously calculates a sum of objects’ specific nullable Int64 fields for a query. Uses a lambda expression to obtain values.

Namespace : DevExpress.Xpo

Assembly : DevExpress.Xpo.v25.2.dll

NuGet Package : DevExpress.Xpo

csharp

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

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

Parameters

Name	Type	Description
query	IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

| | selector | Expression<Func<T, Nullable<Int64>>> |

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<Int64>>

A Task that returns a sum of objects’ specific nullable Int64 fields for a query.