Creating a Custom ObjectDataSource Control - Demo


If you are using the ObjectDataSource control with the same properties on multiple pages, then it's useful to derive a new control from the ObjectDataSource control that has these properties by default. For example, if you are displaying a list of movies un multiple pages, then it would be helpful to create a specialized MovieDataSource control. In this example, the MovieDataSource control derives from the base ObjectDataSource control class. 

<%@ Page Language="VB" %>
<%@ Register TagPrefix="custom" Namespace="StonecoastWebDesign.Samples" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Movie DataSource</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    <asp:GridView
        id="grdMovies"
        DataSourceID="srcMovies"
        Runat="server" />
    
    <custom:MovieDataSource
        id="srcMovies"
        Runat="server" />
    
    </div>
    </form>
</body>
</html>


** MovieDataSource.vb ** 

Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Configuration
Imports System.Web.UI.WebControls

'Namespace AspNetUnleashed.Samples
Namespace StonecoastWebDesign.Samples

    Public Class MovieDataSource
        Inherits ObjectDataSource

        Public Sub New()
            Me.TypeName = "StonecoastWebDesign.Samples.MoviesComponent"
            Me.SelectMethod = "GetMovies"
        End Sub
    End Class

    Public Class MoviesComponent

        Private ReadOnly _conString As String

        Public Function GetMovies() As SqlDataReader
            ' Initialize connection     
            Dim con As New SqlConnection(_conString)

            ' Initialize command
            Dim cmd As New SqlCommand()
            cmd.Connection = con
            cmd.CommandText = "SELECT Title,Director,DateReleased FROM Movies"

            ' Execute command
            con.Open()
            Return cmd.ExecuteReader(CommandBehavior.CloseConnection)
        End Function

        Sub New()
            _conString = WebConfigurationManager.ConnectionStrings("MyDatabase").ConnectionString
        End Sub
    End Class
End Namespace