ADO.NET DataExtender allows defining of different aspects of visual data representation in ComponentOne UI controls on a data level. For example, you can define, format, or edit mask for a certain column. You also set it up to have a lookup combo box or any other ComponentOne control that supports this feature. Simply by being connected to this column, the ComponentOne control will automatically reflect those definitions.

In order to allow defining of UI related properties, ADO.NET DataExtender offers the C1ViewColumn.ColumnStyle property. The C1ViewColumn.ColumnStyle property contains subproperties, such as Format, EditMask and Visible that make it possible to define different aspects of column data representation in UI.

The current set of controls that support column styles includes True DBGrid for WinForms, FlexGrid for WinForms, and Input for WinForms.

In addition to defining visual data representation, calculations can be defined to determine the final value of C1ViewColumn. The calculations can be defined in three ways:

• By the DataColumnExtender.CalculationExpression property of the DataColumnExtender (DataSetExtender column) and C1ViewColumn (C1DataView column) objects. In this case an expression can be written using the syntax of an arbitrary .NET Framework programming language available on your computer.
• By an event handler method of the C1DataViewSet.CalculateColumn event.
• By the C1DataView Definition Statement Builder of the Definition property. See C1DataView Definitions for additional information.