IDataItemContainer Interface

Enables data-bound control containers to identify a data item object for simplified data-binding operations.

Namespace: System.Web.UI
Assembly: System.Web (in system.web.dll)

Public Interface IDataItemContainer
	Inherits INamingContainer
Dim instance As IDataItemContainer

public interface IDataItemContainer extends INamingContainer
public interface IDataItemContainer extends INamingContainer
Not applicable.

Container classes that implement the IDataItemContainer interface can specify which of their properties identifies the data item for data-binding operations, such as late binding with the DataBinder class.

The following code example demonstrates how to use the IDataItemContainer interface. The SimpleSpreadsheetControl is a control that displays tabular-style data, similar to a DataGrid or GridView control. It contains a set of SimpleSpreadsheetRow objects.

The SimpleSpreadsheetRow class is a container class that implements the IDataItemContainer interface. Although in this example the data item property is intuitively named Data, the DataItem property can be implemented to map to any property or return value of a method.

Imports System
Imports System.Collections
Imports System.Data.Common
Imports System.Web.UI
Imports System.Web.UI.WebControls

Namespace Samples.AspNet.VB

    Public Class SimpleSpreadsheetControl
        Inherits CompositeDataBoundControl

        Protected table As New Table()

        Public Overridable ReadOnly Property Rows() As TableRowCollection
                Return table.Rows
            End Get
        End Property

        Protected Overrides Function CreateChildControls(ByVal dataSource As IEnumerable, ByVal dataBinding As Boolean) As Integer

            Dim count As Integer = 0
            ' If dataSource is not Nothing, iterate through it and
            ' extract each element from it as a row, then
            ' create a SimpleSpreadsheetRow and add it to the
            ' rows collection.
            If Not (dataSource Is Nothing) Then

                Dim row As SimpleSpreadsheetRow
                Dim e As IEnumerator = dataSource.GetEnumerator()

                While e.MoveNext()
                    Dim datarow As Object = e.Current
                    row = New SimpleSpreadsheetRow(count, datarow)
                    count += 1
                End While

            End If
            Return count
        End Function 'CreateChildControls
    End Class 'SimpleSpreadsheetControl

    Public Class SimpleSpreadsheetRow
        Inherits TableRow
        Implements IDataItemContainer

        Private dataObj As Object
        Private _itemIndex As Integer

        Public Sub New(ByVal itemIndex As Integer, ByVal o As Object)
            dataObj = o
            _itemIndex = itemIndex
        End Sub 'New

        Public Overridable ReadOnly Property Data() As Object
                Return dataObj
            End Get
        End Property

        ReadOnly Property DataItem() As Object Implements IDataItemContainer.DataItem
                Return Data
            End Get
        End Property

        ReadOnly Property DataItemIndex() As Integer Implements IDataItemContainer.DataItemIndex
                Return _itemIndex
            End Get
        End Property

        ReadOnly Property DisplayIndex() As Integer Implements IDataItemContainer.DisplayIndex
                Return _itemIndex
            End Get
        End Property
        Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter)

            If Not (Data Is Nothing) Then
                If TypeOf Data Is System.Data.Common.DbDataRecord Then
                    Dim temp As DbDataRecord = CType(Data, DbDataRecord)
                    Dim i As Integer

                    While i < temp.FieldCount
                        i += 1
                    End While
                    writer.Write(("<TD>" + Data.ToString() + "</TD>"))
                End If

                writer.Write("<TD>This is a test</TD>")
            End If
        End Sub 'RenderContents
    End Class 'SimpleSpreadsheetRow
End Namespace

The following code example demonstrates how to use the SimpleSpreadsheetControl and AccessDataSource control to display data in an Access database.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB"
    Assembly="Samples.AspNet.VB" %>
<%@ Page language="vb" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<html xmlns="" >
    <title>IDataItemContainer - VB Example</title>
    <form id="Form1" method="post" runat="server">

          datasourceid="AccessDataSource1" />

          SelectCommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
          FROM Orders WHERE EmployeeID =
          (SELECT EmployeeID FROM Employees WHERE LastName = 'King')">


Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0