'Declaration Public Overrides Sub BeginCalculation( _ ByVal summaryResult As SummaryResult _ )
public override void BeginCalculation( SummaryResult summaryResult )
This method is called to start calculation of a summary for a particular set of data (associated with the records parameter). Typically you initialize any member variables in this method. For example, for a calculator that performs summation, you would initialize the sum member variable to 0. In Aggregate, you would add each value to the sum. In EndCalculation, you would return the result of the calculation.
Note that summaryResult parameter is for extra context only and typically it's not necessary to use it or take it into account for calculation purposes.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2