HtmlSelect.AddParsedSubObject(Object) Methode

Definition

Namespace:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Fügt dem HtmlSelect Steuerelement ein analysiertes untergeordnetes Steuerelement hinzu.

protected:
 override void AddParsedSubObject(System::Object ^ obj);
protected override void AddParsedSubObject(object obj);
override this.AddParsedSubObject : obj -> unit
Protected Overrides Sub AddParsedSubObject (obj As Object)

Parameter

obj
Object

Das analysierte untergeordnete Steuerelement, das hinzugefügt werden soll.

Implementiert

AddParsedSubObject(Object)

Ausnahmen

HttpException

Das durch den obj Parameter angegebene untergeordnete Steuerelement muss vom Typ ListItemsein.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die AddParsedSubObject Methode in einem benutzerdefinierten Serversteuerelement überschreibt, sodass immer überprüft wird, ob eine Instanz der ListItem Klasse der HtmlSelect ausgewählten Elementauflistung hinzugefügt wird.

<%@ 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 - AddParsedSubObject - C# Example</title>
        <script runat="server">
      void HtmlInputButton1_ServerClick(Object sender, EventArgs e) 
      {
        if (HtmlSelect1.SelectedIndex >= 0)
        {
          if (HtmlSelect1.Multiple)
          {
            Div1.InnerHtml = "You selected:";
            for (int i=0; i<=HtmlSelect1.Items.Count - 1; i++)
            {
              if (HtmlSelect1.Items[i].Selected)
              {
                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 - AddParsedSubObject - C# Example</h3>
            
            <p>
      <aspSample:CustomHtmlSelectAddParsedSubObject 
        id="HtmlSelect1" 
        name="HtmlSelect1"
        runat="server">
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>
        <option value="Option3">Option3</option>
      </aspSample:CustomHtmlSelectAddParsedSubObject>
      </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 - AddParsedSubObject - 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 - AddParsedSubObject - VB.NET Example</h3>
            
            <p>
      <aspSample:CustomHtmlSelectAddParsedSubObject 
        id="HtmlSelect1" 
        name="HtmlSelect1"
        runat="server">
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>
        <option value="Option3">Option3</option>
      </aspSample:CustomHtmlSelectAddParsedSubObject>
      </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 CustomHtmlSelectAddParsedSubObject : System.Web.UI.HtmlControls.HtmlSelect
    {
        protected override void AddParsedSubObject(object obj)
        {
            // If the object is a ListItem, then add the ListItem to the Items collection.
            if (obj is System.Web.UI.WebControls.ListItem)
            {
            Items.Add((System.Web.UI.WebControls.ListItem)obj);
            }
            else
            {
            throw new System.Web.HttpException("You cannot have a child control of type " + obj.GetType().Name.ToString());
            }
        }
    }
}

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

    Protected Overrides Sub AddParsedSubObject(ByVal obj As Object)

        ' If the object is a ListItem, then add the ListItem to the Items collection.
        If TypeOf obj Is System.Web.UI.WebControls.ListItem Then
            Items.Add(CType(obj, System.Web.UI.WebControls.ListItem))
        Else
            Throw New System.Web.HttpException("You cannot have a child control of type " + obj.GetType().Name.ToString())
        End If
    End Sub
End Class

Hinweise

Die methode AddParsedSubObject wird von ASP.NET verwendet, um analysierte untergeordnete Steuerelemente zum steuerelement HtmlSelect hinzuzufügen.

Gilt für: