'宣言 Public MustInherit Class AverageAggregator(Of T) Implements IAggregator, Infragistics.Olap.IAggregator(Of Nullable(Of Decimal),AverageValue(Of T),T)
public abstract class AverageAggregator<T> : IAggregator, Infragistics.Olap.IAggregator<Nullable<decimal>,AverageValue<T>,T>