IDataItemContainer IDataItemContainer IDataItemContainer IDataItemContainer Interface

Definition

Hiermit können datengebundene Steuerelementcontainer ein Datenelementobjekt für vereinfachte Datenbindungsvorgänge identifizieren.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
Abgeleitet
Implementiert

Beispiele

Im folgenden Codebeispiel wird die Verwendung der IDataItemContainer -Schnittstelle veranschaulicht.The following code example demonstrates how to use the IDataItemContainer interface. Das SimpleSpreadsheetControl -Steuerelement ist ein Steuerelement, das tabellarische Daten anzeigt DataGrid , GridView ähnlich wie ein-oder-Steuerelement.The SimpleSpreadsheetControl is a control that displays tabular-style data, similar to a DataGrid or GridView control. Sie enthält eine Reihe von SimpleSpreadsheetRow -Objekten.It contains a set of SimpleSpreadsheetRow objects.

Die SimpleSpreadsheetRow -Klasse ist eine Container Klasse, die IDataItemContainer die-Schnittstelle implementiert.The SimpleSpreadsheetRow class is a container class that implements the IDataItemContainer interface. Obwohl in diesem Beispiel die Datenelement Eigenschaft intuitiv benannt Dataist, kann die DataItem -Eigenschaft implementiert werden, um einer beliebigen Eigenschaft oder einem Rückgabewert einer Methode zuzuordnen.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.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


    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

        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
    End Class
End Namespace

Im folgenden Codebeispiel wird veranschaulicht, wie das SimpleSpreadsheetControl - AccessDataSource Steuerelement und das-Steuerelement zum Anzeigen von Daten in einer Access-Datenbank verwendetThe 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>

Hinweise

Container Klassen, die die IDataItemContainer -Schnittstelle implementieren, können angeben, welche der Eigenschaften das Datenelement für Daten Bindungs Vorgänge identifiziert, z. b DataBinder . späte Bindung mit der-Klasse.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.

Eigenschaften

DataItem DataItem DataItem DataItem

Ruft bei erfolgter Implementierung ein object ab, das in vereinfachten Datenbindungsvorgängen verwendet wird.When implemented, gets an object that is used in simplified data-binding operations.

DataItemIndex DataItemIndex DataItemIndex DataItemIndex

Ruft bei erfolgter Implementierung den Index des an ein Steuerelement gebundenen Datenelements ab.When implemented, gets the index of the data item bound to a control.

DisplayIndex DisplayIndex DisplayIndex DisplayIndex

Ruft bei erfolgter Implementierung die Position des in einem Steuerelement angezeigten Datenelements ab.When implemented, gets the position of the data item as displayed in a control.

Erweiterungsmethoden

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

Ruft die Auflistung der Standardwerte für das angegebene Datensteuerelement ab.Gets the collection of the default values for the specified data control.

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

Ruft die Tabellenmetadaten für das angegebene Datensteuerelement ab.Gets the table metadata for the specified data control.

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

Legt die Tabellenmetadaten für das angegebene Datensteuerelement fest.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>)

Legt die Zuordnung für Tabellenmetadaten und Standardwerte für das angegebene Datensteuerelement fest.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)

Legt die Zuordnung für Tabellenmetadaten und Standardwerte für das angegebene Datensteuerelement fest.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)

Bestimmt, ob Tabellenmetadaten verfügbar sind.Determines whether table metadata is available.

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

Aktiviert das Verhalten dynamischer Daten für das angegebene DatensteuerelementEnables 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>)

Aktiviert das Verhalten dynamischer Daten für das angegebene DatensteuerelementEnables Dynamic Data behavior for the specified data control.

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

Aktiviert das Verhalten dynamischer Daten für das angegebene DatensteuerelementEnables Dynamic Data behavior for the specified data control.

Gilt für:

Siehe auch