Gets or sets the name of the data field which the filter condition is applied to.
A String value that specifies the name of the corresponding data field.
Use the ColumnName property to specify the data field whose values are taken in account when applying the filter condition defined by the current filter item. The ColumnName property specifies the name of the required data field from the data source which the corresponding series is bound to. Note that the series should be bound to the specified field (either via its Series.ArgumentDataMember or Series.ValueDataMember property) in order for the applied filtering to take effect.