IDataItemContainer Interface
Enables data-bound control containers to identify a data item object for simplified data-binding operations.
Assembly: System.Web (in System.Web.dll)
'Declaration <AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level := AspNetHostingPermissionLevel.Minimal)> _ <AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level := AspNetHostingPermissionLevel.Minimal)> _ Public Interface IDataItemContainer _ Inherits INamingContainer 'Usage Dim instance As IDataItemContainer
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.
| Topic | Location |
|---|---|
| How to: Access Members of a Web Server Control's Naming Container | Building ASP .NET Web Applications |
| How to: Access Members of a Web Server Control's Naming Container | Building ASP .NET Web Applications |
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>
- AspNetHostingPermission
for operating in a hosted environment. Associated enumeration: Minimal
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.