HtmlTable.RenderChildren(HtmlTextWriter) Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Esegue il rendering dei controlli figlio del controllo HtmlTable sull'oggetto HtmlTextWriter specificato.

protected:
 override void RenderChildren(System::Web::UI::HtmlTextWriter ^ writer);
protected public:
 override void RenderChildren(System::Web::UI::HtmlTextWriter ^ writer);
protected override void RenderChildren (System.Web.UI.HtmlTextWriter writer);
protected internal override void RenderChildren (System.Web.UI.HtmlTextWriter writer);
override this.RenderChildren : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub RenderChildren (writer As HtmlTextWriter)
Protected Friend Overrides Sub RenderChildren (writer As HtmlTextWriter)

Parametri

writer
HtmlTextWriter

Oggetto HtmlTextWriter che riceve il contenuto di cui è stato eseguito il rendering.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del RenderChildren metodo in un controllo server personalizzato in modo che al controllo venga aggiunta una nuova riga di HtmlTable tabella.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<!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 HtmlTable - RenderChildren Example</title>
    </head>
    <body>
        <form id="Form1" 
          method="post" 
          runat="server">
            <h3>Custom HtmlTable - RenderChildren Example</h3>
      
      <aspSample:CustomHtmlTableRenderChildren 
        id="HtmlTable1" 
        name="HtmlTable1" 
        runat="server" 
        border="1"
        cellSpacing="0" 
        cellPadding="5">
        <tr>
          <td>1,1</td>
          <td>1,2</td>
          <td>1,3</td>
        </tr>
        <tr>
          <td>2,1</td>
          <td>2,2</td>
          <td>2,3</td>
        </tr>
        <tr>
          <td>3,1</td>
          <td>3,2</td>
          <td>3,3</td>
        </tr>
      </aspSample:CustomHtmlTableRenderChildren>

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

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<!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 HtmlTable - RenderChildren Example</title>
    </head>
    <body>
        <form id="Form1" 
          method="post" 
          runat="server">
            <h3>Custom HtmlTable - RenderChildren Example</h3>
      
      <aspSample:CustomHtmlTableRenderChildren 
        id="HtmlTable1" 
        name="HtmlTable1" 
        runat="server" 
        border="1"
        cellSpacing="0" 
        cellPadding="5">
        <tr>
          <td>1,1</td>
          <td>1,2</td>
          <td>1,3</td>
        </tr>
        <tr>
          <td>2,1</td>
          <td>2,2</td>
          <td>2,3</td>
        </tr>
        <tr>
          <td>3,1</td>
          <td>3,2</td>
          <td>3,3</td>
        </tr>
      </aspSample:CustomHtmlTableRenderChildren>

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

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlTableRenderChildren : System.Web.UI.HtmlControls.HtmlTable
    {
        protected override void RenderChildren(System.Web.UI.HtmlTextWriter writer)
        {
            // Call the base class's RenderChildren method.
            base.RenderChildren(writer);
            
            // Write out a new table row.
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Tr);
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Td);
            writer.Write("4,1");
            writer.RenderEndTag();
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Td);
            writer.Write("4,2");
            writer.RenderEndTag();
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Td);
            writer.Write("4,3");
            writer.RenderEndTag();
            writer.RenderEndTag();
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomHtmlTableRenderChildren
        Inherits System.Web.UI.HtmlControls.HtmlTable

        Protected Overrides Sub RenderChildren(ByVal writer As System.Web.UI.HtmlTextWriter)

            ' Call the base class's RenderChildren method.
            MyBase.RenderChildren(writer)

            ' Write out a new table row.
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Tr)
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Td)
            writer.Write("4,1")
            writer.RenderEndTag()
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Td)
            writer.Write("4,2")
            writer.RenderEndTag()
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Td)
            writer.Write("4,3")
            writer.RenderEndTag()
            writer.RenderEndTag()
        End Sub
    End Class
End Namespace

Commenti

Il RenderChildren metodo fornisce una formattazione aggiuntiva prima e dopo aver chiamato il metodo della classe di Control.RenderChildren base. La formattazione aggiuntiva rende più semplice leggere il codice HTML sottoposto a rendering del HtmlTable controllo inserendo una riga restituita e rientrando prima di eseguire il HtmlTable rendering dei controlli figlio del controllo.

Il RenderChildren metodo viene usato principalmente dagli sviluppatori di controlli che estendono la funzionalità del HtmlTable controllo.

Si applica a

Vedi anche