'Declaration
 
Public Overloads Shared Function LiveSum(Of TSource)( _
   ByVal source As View(Of TSource), _
   ByVal selector As System.Linq.Expressions.Expression(Of Func(Of TSource,Decimal)) _
) As AggregationView(Of TSource,Decimal)

public static AggregationView<TSource,decimal> LiveSum<TSource>( 
   View<TSource> source,
   System.Linq.Expressions.Expression<Func<TSource,decimal>> selector
)

Parameters

source

A view containing the values to calculate the sum of.

selector

A transform function to apply to each element.

Type Parameters

TSource

The type of the elements of source.

Return Value

If the source is empty or contains only nulls, the sum value is zero.

It is possible to use standard LINQ query operator Sum instead of LiveSum. Both are "live" in the sense that they are recomputed automatically when any change occurs in the source. The difference is that Sum will every time loop through the entire source collection and aggregate it from scratch, whereas LiveSum will use a more performant algorithm, will maintain its value incrementally, processing only those source items that actually changed.

Reference

LiveViewExtensions Class
LiveViewExtensions Members
Overload List