IDataItemContainer IDataItemContainer IDataItemContainer IDataItemContainer Interface

Definizione

Consente ai contenitori di controlli con associazione a dati di identificare un oggetto dati per semplificare le operazioni di associazione dati.Enables data-bound control containers to identify a data item object for simplified data-binding operations.

public interface class IDataItemContainer : System::Web::UI::INamingContainer
public interface IDataItemContainer : System.Web.UI.INamingContainer
type IDataItemContainer = interface
    interface INamingContainer
Public Interface IDataItemContainer
Implements INamingContainer
Derivato
Implementazioni

Esempi

Esempio di codice seguente viene illustrato come utilizzare il IDataItemContainer interfaccia.The following code example demonstrates how to use the IDataItemContainer interface. Il SimpleSpreadsheetControl è un controllo che consente di visualizzare dati in formato, simile a un DataGrid o GridView controllo.The SimpleSpreadsheetControl is a control that displays tabular-style data, similar to a DataGrid or GridView control. Contiene un set di SimpleSpreadsheetRow oggetti.It contains a set of SimpleSpreadsheetRow objects.

Il SimpleSpreadsheetRow classe è una classe contenitore che implementa il IDataItemContainer interfaccia.The SimpleSpreadsheetRow class is a container class that implements the IDataItemContainer interface. Sebbene in questo esempio la proprietà dell'elemento dati è stata denominata Data, il DataItem proprietà può essere implementata per eseguire il mapping a qualsiasi valore restituito o di proprietà di un metodo.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.

using System;
using System.Collections;
using System.Data.Common;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Samples.AspNet.CS
{
    public class SimpleSpreadsheetControl : CompositeDataBoundControl
    {
        protected Table table = new Table();

        public virtual TableRowCollection Rows
        {
            get
            {
                return table.Rows;
            }
        }

        protected override int CreateChildControls(IEnumerable dataSource, bool dataBinding)
        {

            int count = 0;
            // If dataSource is not null, iterate through it and
            // extract each element from it as a row, then
            // create a SimpleSpreadsheetRow and add it to the
            // rows collection.
            if (dataSource != null)
            {

                SimpleSpreadsheetRow row;
                IEnumerator e = dataSource.GetEnumerator();

                while (e.MoveNext())
                {
                    object datarow = e.Current;
                    row = new SimpleSpreadsheetRow(count, datarow);
                    this.Rows.Add(row);
                    ++count;
                }

                Controls.Add(table);
            }
            return count;
        }
    }

    //
    //
    public class SimpleSpreadsheetRow : TableRow, IDataItemContainer
    {
        private object data;
        private int _itemIndex;

        public SimpleSpreadsheetRow(int itemIndex, object o)
        {
            data = o;
            _itemIndex = itemIndex;
        }

        public virtual object Data
        {
            get
            {
                return data;
            }
        }
        object IDataItemContainer.DataItem
        {
            get
            {
                return Data;
            }
        }
        int IDataItemContainer.DataItemIndex
        {
            get
            {
                return _itemIndex;
            }
        }
        int IDataItemContainer.DisplayIndex
        {
            get
            {
                return _itemIndex;
            }
        }
        protected override void RenderContents(HtmlTextWriter writer)
        {

            if (Data != null)
            {
                if (Data is System.Data.Common.DbDataRecord)
                {
                    DbDataRecord temp = (DbDataRecord)Data;
                    for (int i = 0; i < temp.FieldCount; ++i)
                    {
                        writer.Write("<TD>");
                        writer.Write(temp.GetValue(i).ToString());
                        writer.Write("</TD>");
                    }
                }
                else
                    writer.Write("<TD>" + Data.ToString() + "</TD>");
            }

            else
                writer.Write("<TD>This is a test</TD>");
        }
    }
}
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

Esempio di codice seguente viene illustrato come utilizzare il SimpleSpreadsheetControl e AccessDataSource controllo per visualizzare i dati in un database di Access.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.CS"
    Assembly="Samples.AspNet.CS"  %>
<%@ Page language="c#" %>
<!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 - C# 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>
<%@ 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>

Commenti

Contenitore di classi che implementano il IDataItemContainer interfaccia è possibile specificare che delle relative proprietà identifica l'elemento di dati per le operazioni di data binding, come l'associazione tardiva con il DataBinder classe.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.

Proprietà

DataItem DataItem DataItem DataItem

Se implementata, ottiene un elemento object utilizzato nelle operazioni semplificate di associazione dati.When implemented, gets an object that is used in simplified data-binding operations.

DataItemIndex DataItemIndex DataItemIndex DataItemIndex

Se implementata, ottiene l'indice dell'elemento di dati associato a un controllo.When implemented, gets the index of the data item bound to a control.

DisplayIndex DisplayIndex DisplayIndex DisplayIndex

Se implementata, ottiene la posizione dell'elemento di dati visualizzato in un controllo.When implemented, gets the position of the data item as displayed in a control.

Extension Methods

GetDefaultValues(INamingContainer) GetDefaultValues(INamingContainer) GetDefaultValues(INamingContainer) GetDefaultValues(INamingContainer)

Ottiene l'insieme di valori predefiniti per il controllo dei dati specificato.Gets the collection of the default values for the specified data control.

GetMetaTable(INamingContainer) GetMetaTable(INamingContainer) GetMetaTable(INamingContainer) GetMetaTable(INamingContainer)

Ottiene i metadati della tabella per il controllo dei dati specificato.Gets the table metadata for the specified data control.

SetMetaTable(INamingContainer, MetaTable) SetMetaTable(INamingContainer, MetaTable) SetMetaTable(INamingContainer, MetaTable) SetMetaTable(INamingContainer, MetaTable)

Imposta i metadati della tabella per il controllo dei dati specificato.Sets the table metadata for the specified data control.

SetMetaTable(INamingContainer, MetaTable, IDictionary<String,Object>) SetMetaTable(INamingContainer, MetaTable, IDictionary<String,Object>) SetMetaTable(INamingContainer, MetaTable, IDictionary<String,Object>) SetMetaTable(INamingContainer, MetaTable, IDictionary<String,Object>)

Imposta il mapping dei valori predefiniti e dei metadati della tabella per il controllo dei dati specificato.Sets the table metadata and default value mapping for the specified data control.

SetMetaTable(INamingContainer, MetaTable, Object) SetMetaTable(INamingContainer, MetaTable, Object) SetMetaTable(INamingContainer, MetaTable, Object) SetMetaTable(INamingContainer, MetaTable, Object)

Imposta il mapping dei valori predefiniti e dei metadati della tabella per il controllo dei dati specificato.Sets the table metadata and default value mapping for the specified data control.

TryGetMetaTable(INamingContainer, MetaTable) TryGetMetaTable(INamingContainer, MetaTable) TryGetMetaTable(INamingContainer, MetaTable) TryGetMetaTable(INamingContainer, MetaTable)

Determina se sono disponibili i metadati della tabella.Determines whether table metadata is available.

EnableDynamicData(INamingContainer, Type) EnableDynamicData(INamingContainer, Type) EnableDynamicData(INamingContainer, Type) EnableDynamicData(INamingContainer, Type)

Abilita il comportamento dati dinamici per il controllo dei dati specificato.Enables Dynamic Data behavior for the specified data control.

EnableDynamicData(INamingContainer, Type, IDictionary<String,Object>) EnableDynamicData(INamingContainer, Type, IDictionary<String,Object>) EnableDynamicData(INamingContainer, Type, IDictionary<String,Object>) EnableDynamicData(INamingContainer, Type, IDictionary<String,Object>)

Abilita il comportamento dati dinamici per il controllo dei dati specificato.Enables Dynamic Data behavior for the specified data control.

EnableDynamicData(INamingContainer, Type, Object) EnableDynamicData(INamingContainer, Type, Object) EnableDynamicData(INamingContainer, Type, Object) EnableDynamicData(INamingContainer, Type, Object)

Abilita il comportamento dati dinamici per il controllo dei dati specificato.Enables Dynamic Data behavior for the specified data control.

Si applica a

Vedi anche