Bahasa

CheckBoxList.Render(HtmlTextWriter) Metode

Definisi

Ruang nama:
System.Web.UI.WebControls
Rakitan:
System.Web.dll

Menampilkan pada CheckBoxList klien.

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

Parameter

writer
HtmlTextWriter

HtmlTextWriter yang berisi aliran output untuk penyajian pada klien.

Contoh

Contoh kode berikut menunjukkan cara mengambil alih Render metode dalam kontrol server kustom sehingga CheckBoxList selalu menampilkan gambar.

<%@ 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 - Render - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom CheckBoxList - Render - C# Example</h3>

      <aspSample:CustomCheckBoxListRender
        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:CustomCheckBoxListRender>

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

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" 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>Custom CheckBoxList - Render - VB.NET Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom CheckBoxList - Render - VB.NET Example</h3>
      <aspSample:CustomCheckBoxListRender id="CheckBoxList" runat="server"
       RepeatLayout="Table" RepeatColumns="2" CellSpacing="3" CellPadding="3">
                <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:CustomCheckBoxListRender>
    </form>
  </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomCheckBoxListRender : System.Web.UI.WebControls.CheckBoxList
    {
        protected override void Render(System.Web.UI.HtmlTextWriter writer)
        {
        // Create and render a new Image Web control.
        System.Web.UI.WebControls.Image image = new System.Web.UI.WebControls.Image();
        image.ID = "Image1";
        image.ImageUrl = "image.jpg"; 
        image.AlternateText = "Image for CheckBoxList1.";
        image.RenderControl(writer);

        // Call the base class's Render method.
        base.Render(writer);
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

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

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

            ' Create and render a new Image Web control.
            Dim image As New System.Web.UI.WebControls.Image
            image.ID = "Image1"
            image.ImageUrl = "image.jpg"
            image.AlternateText = "Image for CheckBoxList1."
            image.RenderControl(writer)

            ' Call the base class's Render method.
            MyBase.Render(writer)
        End Sub
    End Class
End Namespace

Keterangan

Metode Render ini digunakan terutama oleh pengembang kontrol dalam kontrol kustom yang berasal dari CheckBoxList kelas .

Implementasi Render untuk CheckBoxList kontrol menginisialisasi RepeatInfo objek untuk daftar, dan memanggil RenderRepeater metode , yang pada gilirannya RenderItem menggunakan metode untuk merender item daftar kotak centang individual.

Berlaku untuk

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