ADO.NET Cookbook

7.17. Using ADO.NET Design-Time Features in Classes Without a GUI

Problem

The design-time environment provides controls and wizards to facilitate creation of and management of properties of ADO.NET objects. You want to use that design-time functionality when creating classes that do not have a GUI.

Solution

Create a component and use its design-time functionality.

The solution contains two parts: the component and the test container for the component. To create the component Component0717.cs, add two controls to its design surface:

• Drop a SqlDataAdapter onto the design surface and use the Data Adapter Configuration Wizard to connect to the Northwind sample database on the local SQL Server. Accept all wizard defaults; supply the following SQL statement when prompted to generate the SQL statements:

  SELECT
      OrderID,
      CustomerID,
      EmployeeID,
      OrderDate,
      RequiredDate,
      ShippedDate,
      ShipVia,
      Freight,
      ShipName,
      ShipAddress,
      ShipCity,
      ShipRegion,
      ShipPostalCode,
      ShipCountry
  FROM
      Orders

  After the wizard completes, rename the SqlDataAdapter control to da.

• A SqlConnection control is automatically added to the design surface when the SqlDataAdapter wizard is completed; rename it to conn.

The sample code for the component exposes one property and one method:

MyDataTable

A read-only property that returns a DataTable filled using the SqlDataAdapter control.

Update( )

This method takes a DataTable object argument that uses the SqlDataAdapter control to update changes to the DataTable (retrieved using the MyDataTable ...