DataList.RenderContents(HtmlTextWriter) Metodo

  • Riferimento

Definizione

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

Esegue il rendering degli elementi di elenco nel controllo DataList.

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

Parametri

writer
HtmlTextWriter

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

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del RenderContents metodo in un controllo server personalizzato in modo che alcuni testo precedono l'oggetto DataList .

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet" 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 DataList - RenderContents - C# Example</title>
        <script runat="server">
          private void Page_Load(object sender, System.EventArgs e)
          {
        // Create sample data for the DataList control.
        System.Data.DataTable dt = new System.Data.DataTable();
        System.Data.DataRow dr;
        dt.Columns.Add(new System.Data.DataColumn("Column1", typeof(String)));
        
        dr = dt.NewRow();
        dr[0] = "Hello";
        dt.Rows.Add(dr);
        
        dr = dt.NewRow();
        dr[0] = "DataList";
        dt.Rows.Add(dr);
        
        dr = dt.NewRow();
        dr[0] = "World";
        dt.Rows.Add(dr);

        // Show the DataTable values in the DataList.
              DataList1.DataSource = dt;
        DataList1.DataBind();
        }        
        </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom DataList - RenderContents - C# Example</h3>

            <aspSample:CustomDataListRenderContents id="DataList1" runat="server" 
                BorderColor="#999999" BorderStyle="None" BackColor="White" CellPadding="3" 
                GridLines="Vertical" BorderWidth="1px" Width="100px">
        
          <HeaderStyle Font-Bold="True" ForeColor="White" BackColor="#000084" />
          <HeaderTemplate>
              <asp:Label id="Label1" runat="server">Column1</asp:Label>
          </HeaderTemplate>

          <ItemStyle ForeColor="Black" BackColor="#EEEEEE" />
          <ItemTemplate>
              <asp:Label id="Label2" runat="server"><%# DataBinder.Eval(Container.DataItem, "Column1") %></asp:Label>
          </ItemTemplate>

          <AlternatingItemStyle BackColor="#DCDCDC" />
          <AlternatingItemTemplate>
              <asp:Label id="Label3" runat="server"><%# DataBinder.Eval(Container.DataItem, "Column1") %></asp:Label>
          </AlternatingItemTemplate>
          
      </aspSample:CustomDataListRenderContents>
        </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 DataList - RenderContents - VB.NET Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom DataList - RenderContents - VB.NET Example</h3>
      <aspSample:CustomDataListRenderContents id="DataList1" runat="server" />
    </form>
  </body>
</html>

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

namespace Samples.AspNet
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomDataListRenderContents : System.Web.UI.WebControls.DataList
    {
        protected override void RenderContents(System.Web.UI.HtmlTextWriter writer)
        {
            // Place some text before the DataList.
            writer.Write("Here is some text from the RenderContent method.<br>");

            // Call the base RenderContents method.
            base.RenderContents(writer);
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

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

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

            ' Place some text before the DataList.
            writer.Write("Here is some text from the RenderContent method.<br>")

            ' Call the base RenderContents method.
            MyBase.RenderContents(writer)
        End Sub
    End Class
End Namespace

Commenti

Il RenderContents metodo viene usato principalmente dagli sviluppatori di controlli, quando deriva un controllo personalizzato dal DataList controllo.

Il RenderContents metodo esegue il rendering del contenuto interno del DataList controllo, inclusi i controlli contenuti DataListItem .

Si applica a