HtmlSelect.RenderChildren(HtmlTextWriter) Yöntem

Başvuru

Tanım

Ad Alanı:: System.Web.UI.HtmlControls

Bütünleştirilmiş Kod:: System.Web.dll

Önemli

Bazı bilgiler ürünün ön sürümüyle ilgilidir ve sürüm öncesinde önemli değişiklikler yapılmış olabilir. Burada verilen bilgilerle ilgili olarak Microsoft açık veya zımni hiçbir garanti vermez.

Denetimin HtmlSelect alt denetimlerini belirtilen HtmlTextWriter nesneye işler.

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)

Parametreler

writer: HtmlTextWriter

İşlenen HtmlTextWriter içeriği alan.

Özel durumlar

HttpException

Birden çok öğe seçildi ancak Multiple özelliği olarak falseayarlandı.

Örnekler

Aşağıdaki kod örneği, her zaman özel HtmlSelect bir sunucu denetiminde RenderChildren varsayılan seçenek metnini görüntülemesi için yönteminin nasıl geçersiz kılındığını gösterir.

<%@ 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 HtmlSelect - RenderChildren - C# Example</title>
        <script runat="server">
      void HtmlInputButton1_ServerClick(Object sender, EventArgs e) 
      {
        if (HtmlSelect1.SelectedIndex >= 0)
        {
          if (HtmlSelect1.Multiple == true)
          {
            Div1.InnerHtml = "You selected:";
            for (int i=0; i<=HtmlSelect1.Items.Count - 1; i++)
            {
              if (HtmlSelect1.Items[i].Selected == true)
              {
                Div1.InnerHtml += "<br />    " + HtmlSelect1.Items[i].Value; 
              }     
            }
          }
          else
          {
            Div1.InnerHtml = "You selected " + HtmlSelect1.Value;
          }
        }
        else
        {
          Div1.InnerHtml = "You did not select an item.";
        }
      }
        </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom HtmlSelect - RenderChildren - C# Example</h3>
            
            <p>
      <aspSample:CustomHtmlSelectRenderChildren 
        id="HtmlSelect1"  multiple
        name="HtmlSelect1"
        runat="server">
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>
        <option value="Option3">Option3</option>
      </aspSample:CustomHtmlSelectRenderChildren>
      </p>
      
      <p>
      <input 
        id="HtmlInputButton1" 
        runat="server" 
        type="button" 
        onserverclick="HtmlInputButton1_ServerClick"
        value="Select" 
        name="HtmlInputButton1" />  
      </p>
      
      <br />
      <div id="Div1" runat="server" 
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
       
        </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 HtmlSelect - RenderChildren - VB.NET Example</title>
        <script runat="server">
      Sub HtmlInputButton1_ServerClick(sender As Object, e As EventArgs)
        If HtmlSelect1.SelectedIndex >= 0 Then
            If HtmlSelect1.Multiple = True Then
              Div1.InnerHtml = "You selected:"
              Dim i As Integer
              For i = 0 To HtmlSelect1.Items.Count - 1
                  If HtmlSelect1.Items(i).Selected = True Then
                    Div1.InnerHtml += "<br />    " & HtmlSelect1.Items(i).Value
                  End If
              Next i
            Else
              Div1.InnerHtml = "You selected " & HtmlSelect1.Value
            End If
        Else
            Div1.InnerHtml = "You did not select an item."
        End If
      End Sub
        </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom HtmlSelect - RenderChildren - VB.NET Example</h3>
            
            <p>
      <aspSample:CustomHtmlSelectRenderChildren 
        id="HtmlSelect1"  multiple
        name="HtmlSelect1"
        runat="server">
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>
        <option value="Option3">Option3</option>
      </aspSample:CustomHtmlSelectRenderChildren>
      </p>
      
      <p>
      <input 
        id="HtmlInputButton1" 
        runat="server" 
        type="button" 
        onserverclick="HtmlInputButton1_ServerClick"
        value="Select" 
        name="HtmlInputButton1" />  
      </p>
      
      <br />
      <div id="Div1" runat="server" 
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
       
        </form>
    </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlSelectRenderChildren : System.Web.UI.HtmlControls.HtmlSelect
    {
        protected override void RenderChildren(System.Web.UI.HtmlTextWriter writer)
        {
            // Create a default OPTION.
            System.Web.UI.WebControls.ListItem listItem = new System.Web.UI.WebControls.ListItem("<Select an option> ","");
            this.Items.Insert(0, listItem);
            
            // Call base's RenderChildren method.
            base.RenderChildren(writer);
        }
    }
}

<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlSelectRenderChildren
    Inherits System.Web.UI.HtmlControls.HtmlSelect

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

        ' Create a default OPTION.
        Dim listItem As New System.Web.UI.WebControls.ListItem("<Select an option> ", "")
        Me.Items.Insert(0, listItem)

        ' Call base's RenderChildren method.
        MyBase.RenderChildren(writer)
    End Sub
End Class

Açıklamalar

yöntemi, RenderChildren temel yöntemi çağırmadan temel sınıfın RenderChildren yöntemini geçersiz kılar. Açma ve kapatma <select> etiketleri arasındaki öğelerin her biri <option> bir value öznitelik, öğe seçilirse bir selected öznitelik ve ilişkili metniyle işlenir.

Birden çok öğe seçildiyse ancak Multiple özelliği olarak falseayarlandıysa, bir HttpException özel durum oluşturulur.

Şunlara uygulanır

Ayrıca bkz.

ListItem

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