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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)

'Declaration
Public Interface IDataItemContainer _
	Inherits INamingContainer

The IDataItemContainer type exposes the following members.

  NameDescription
Public propertyDataItemWhen implemented, gets an object that is used in simplified data-binding operations.
Public propertyDataItemIndexWhen implemented, gets the index of the data item bound to a control.
Public propertyDisplayIndexWhen implemented, gets the position of the data item as displayed in a control.
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  NameDescription
Public Extension MethodEnableDynamicData(Type)Overloaded. Enables Dynamic Data behavior for the specified data control. (Defined by DataControlExtensions.)
Public Extension MethodEnableDynamicData(Type, Object)Overloaded. Enables Dynamic Data behavior for the specified data control. (Defined by DataControlExtensions.)
Public Extension MethodEnableDynamicData(Type, IDictionary(Of String, Object))Overloaded. Enables Dynamic Data behavior for the specified data control. (Defined by DataControlExtensions.)
Public Extension MethodGetDefaultValuesGets the collection of the default values for the specified data control. (Defined by DynamicDataExtensions.)
Public Extension MethodGetMetaTableGets the table metadata for the specified data control. (Defined by DynamicDataExtensions.)
Public Extension MethodSetMetaTable(MetaTable)Overloaded. Sets the table metadata for the specified data control. (Defined by DynamicDataExtensions.)
Public Extension MethodSetMetaTable(MetaTable, IDictionary(Of String, Object))Overloaded. Sets the table metadata and default value mapping for the specified data control. (Defined by DynamicDataExtensions.)
Public Extension MethodSetMetaTable(MetaTable, Object)Overloaded. Sets the table metadata and default value mapping for the specified data control. (Defined by DynamicDataExtensions.)
Public Extension MethodTryGetMetaTableDetermines whether table metadata is available. (Defined by DynamicDataExtensions.)
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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
            Get 
                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)
                    Me.Rows.Add(row)
                    count += 1
                End While

                Controls.Add(table)
            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 
            Get 
                Return dataObj
            End Get 
        End Property 

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

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

        ReadOnly Property DisplayIndex() As Integer Implements IDataItemContainer.DisplayIndex
            Get 
                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
                        writer.Write("<TD>")
                        writer.Write(temp.GetValue(i).ToString())
                        writer.Write("</TD>")
                        i += 1
                    End While 
                Else
                    writer.Write(("<TD>" + Data.ToString() + "</TD>"))
                End If 

            Else
                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"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>IDataItemContainer - VB Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">

      <aspSample:SimpleSpreadsheetControl
          id="SimpleSpreadsheet1"
          runat="server"
          datasourceid="AccessDataSource1" />

      <asp:accessdatasource
          id="AccessDataSource1"
          runat="server"
          datasourcemode="DataReader"
          datafile="Northwind.mdb"
          SelectCommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
          FROM Orders WHERE EmployeeID =
          (SELECT EmployeeID FROM Employees WHERE LastName = 'King')">
      </asp:accessdatasource>

    </form>
  </body>
</html>

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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