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CheckBoxList.IRepeatInfoUser.RenderItem Metodo

Definizione

Per una descrizione di questo membro, vedere RenderItem(ListItemType, Int32, RepeatInfo, HtmlTextWriter).

 virtual void System.Web.UI.WebControls.IRepeatInfoUser.RenderItem(System::Web::UI::WebControls::ListItemType itemType, int repeatIndex, System::Web::UI::WebControls::RepeatInfo ^ repeatInfo, System::Web::UI::HtmlTextWriter ^ writer) = System::Web::UI::WebControls::IRepeatInfoUser::RenderItem;
void IRepeatInfoUser.RenderItem (System.Web.UI.WebControls.ListItemType itemType, int repeatIndex, System.Web.UI.WebControls.RepeatInfo repeatInfo, System.Web.UI.HtmlTextWriter writer);
abstract member System.Web.UI.WebControls.IRepeatInfoUser.RenderItem : System.Web.UI.WebControls.ListItemType * int * System.Web.UI.WebControls.RepeatInfo * System.Web.UI.HtmlTextWriter -> unit
override this.System.Web.UI.WebControls.IRepeatInfoUser.RenderItem : System.Web.UI.WebControls.ListItemType * int * System.Web.UI.WebControls.RepeatInfo * System.Web.UI.HtmlTextWriter -> unit
Sub RenderItem (itemType As ListItemType, repeatIndex As Integer, repeatInfo As RepeatInfo, writer As HtmlTextWriter) Implements IRepeatInfoUser.RenderItem

Parametri

itemType
ListItemType

Uno dei valori dell'enumerazione ListItemType.

repeatIndex
Int32

Indice ordinale che specifica la posizione dell'elemento nel controllo elenco.

repeatInfo
RepeatInfo

Oggetto RepeatInfo che rappresenta le informazioni usate per visualizzare l'elemento nell'elenco.

writer
HtmlTextWriter

Oggetto HtmlTextWriter che rappresenta il flusso di output per il rendering del contenuto HTML nel client.

Implementazioni

Esempio

Nell'esempio di codice seguente viene illustrato come usare i membri dell'interfaccia IRepeatInfoUser in un oggetto personalizzato CheckBoxList .

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" 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>Custom CheckBoxList - IRepeatInfoUser - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom CheckBoxList - IRepeatInfoUser - C# Example</h3>
      <aspSample:CustomCheckBoxListIRepeatInfoUser
        id="CheckBoxList1" runat="server">
          <asp:ListItem Selected="True">Item 1</asp:ListItem>
          <asp:ListItem>Item 2</asp:ListItem>
          <asp:ListItem>Item 3</asp:ListItem>
          <asp:ListItem>Item 4</asp:ListItem>
          <asp:ListItem>Item 5</asp:ListItem>
          <asp:ListItem>Item 6</asp:ListItem>
      </aspSample:CustomCheckBoxListIRepeatInfoUser>
    </form>
  </body>
</html>
<%@ Page language="VB" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.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>Custom CheckBoxList - IRepeatInfoUser - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom CheckBoxList - IRepeatInfoUser - VB.NET Example</h3>
      <aspSample:CustomCheckBoxListIRepeatInfoUser id="CheckBoxList" runat="server">
                <asp:ListItem  Selected="True">Item 1</asp:ListItem>
                <asp:ListItem>Item 2</asp:ListItem>
                <asp:ListItem>Item 3</asp:ListItem>
                <asp:ListItem>Item 4</asp:ListItem>
                <asp:ListItem>Item 5</asp:ListItem>
                <asp:ListItem>Item 6</asp:ListItem>
            </aspSample:CustomCheckBoxListIRepeatInfoUser>
        </form>
    </body>
</html>
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = 
        AspNetHostingPermissionLevel.Minimal)]
    public class CustomCheckBoxListIRepeatInfoUser : CheckBoxList
    {
        private bool hasFooter;
        private bool hasHeader;
        private bool hasSeparators;
        private int repeatedItemCount;
        private Style itemStyleItem;

        protected override void OnPreRender(System.EventArgs e)
        {
            // Call the base class's OnPreRender method
            base.OnPreRender(e);

            // Get a self-referencing IRepeatInfoUser object
            IRepeatInfoUser repeatInfoUser = (IRepeatInfoUser)this;

            // Get the IRepeatInfoUser members values.
            hasFooter = repeatInfoUser.HasFooter;
            hasHeader = repeatInfoUser.HasHeader;
            hasSeparators = repeatInfoUser.HasSeparators;
            repeatedItemCount = repeatInfoUser.RepeatedItemCount;
            itemStyleItem = repeatInfoUser.GetItemStyle(ListItemType.Item, 0);
        }

        protected override void Render(HtmlTextWriter writer)
        {
            // Create and setup a RepeatInfo class.
            RepeatInfo repeatInfo = new RepeatInfo();
            repeatInfo.RepeatColumns = 0;
            repeatInfo.RepeatDirection = RepeatDirection.Horizontal;
            repeatInfo.RepeatLayout = RepeatLayout.Table;

            // Get a self-referencing IRepeatInfoUser object
            IRepeatInfoUser repeatInfoUser = (IRepeatInfoUser)this;

            // Render the items using the above RepeatInfo class.
            repeatInfoUser.RenderItem(ListItemType.Item, 0, repeatInfo, writer);
            repeatInfoUser.RenderItem(ListItemType.Item, 1, repeatInfo, writer);
            repeatInfoUser.RenderItem(ListItemType.Item, 2, repeatInfo, writer);
            repeatInfoUser.RenderItem(ListItemType.Item, 3, repeatInfo, writer);
            repeatInfoUser.RenderItem(ListItemType.Item, 4, repeatInfo, writer);
            repeatInfoUser.RenderItem(ListItemType.Item, 5, repeatInfo, writer);
        }
    }
}
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls

    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public Class CustomCheckBoxListIRepeatInfoUser
        Inherits CheckBoxList

        Private _hasFooter As Boolean
        Private _hasHeader As Boolean
        Private _hasSeparators As Boolean
        Private _repeatedItemCount As Integer
        Private _itemStyleItem As Style

        Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
            ' Call the base class's OnPreRender method
            MyBase.OnPreRender(e)

            ' Get a self-referencing IRepeatInfoUser object
            Dim repeatInfoUser As IRepeatInfoUser
            repeatInfoUser = CType(Me, IRepeatInfoUser)

            ' Get the IRepeatInfoUser member values.
            _hasFooter = repeatInfoUser.HasFooter
            _hasHeader = repeatInfoUser.HasHeader
            _hasSeparators = repeatInfoUser.HasSeparators
            _repeatedItemCount = repeatInfoUser.RepeatedItemCount
            _itemStyleItem = repeatInfoUser.GetItemStyle(ListItemType.Item, 0)
        End Sub

        Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
            ' Create and setup a RepeatInfo class.
            Dim repeatInfo As New RepeatInfo
            repeatInfo.RepeatColumns = 0
            repeatInfo.RepeatDirection = RepeatDirection.Horizontal
            repeatInfo.RepeatLayout = RepeatLayout.Table

            ' Get a self-referencing IRepeatInfoUser object
            Dim repeatInfoUser As IRepeatInfoUser
            repeatInfoUser = CType(Me, IRepeatInfoUser)

            ' Render the items using the above RepeatInfo and IRepeatInfoUser classes.
            repeatInfoUser.RenderItem(ListItemType.Item, 0, repeatInfo, writer)
            repeatInfoUser.RenderItem(ListItemType.Item, 1, repeatInfo, writer)
            repeatInfoUser.RenderItem(ListItemType.Item, 2, repeatInfo, writer)
            repeatInfoUser.RenderItem(ListItemType.Item, 3, repeatInfo, writer)
            repeatInfoUser.RenderItem(ListItemType.Item, 4, repeatInfo, writer)
            repeatInfoUser.RenderItem(ListItemType.Item, 5, repeatInfo, writer)
        End Sub
    End Class

End Namespace

Commenti

In genere, è consigliabile usare il metodo per eseguire il CheckBoxList.RenderItem rendering degli elementi in un CheckBoxList oggetto .

Il IRepeatInfoUser.RenderItem metodo è un'implementazione esplicita del membro dell'interfaccia. Può essere utilizzato solo quando si esegue il cast dell'istanza CheckBoxList a un'interfaccia IRepeatInfoUser.

Note per gli eredi

Per definire un'implementazione personalizzata per il rendering degli elementi in un CheckBoxList oggetto, eseguire l'override del RenderItem(ListItemType, Int32, RepeatInfo, HtmlTextWriter) membro. L'implementazione esplicita dell'interfaccia chiama il metodo per eseguire il RenderItem(ListItemType, Int32, RepeatInfo, HtmlTextWriter) rendering di un elemento nel controllo .

Si applica a

Vedi anche