HtmlSelect.AddParsedSubObject(Object) Método

  • Referencia

Definición

Espacio de nombres:
System.Web.UI.HtmlControls
Ensamblado:
System.Web.dll

Agrega un control secundario analizado al control HtmlSelect.

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)

Parámetros

obj
Object

Control secundario analizado que se va a agregar.

Implementaciones

AddParsedSubObject(Object)

Excepciones

HttpException

El control secundario que especifica el parámetro obj debe ser del tipo ListItem.

Ejemplos

En el ejemplo de código siguiente se muestra cómo invalidar el AddParsedSubObject método en un control de servidor personalizado para que siempre compruebe que se agrega una instancia de la ListItem clase a la HtmlSelect colección de elementos seleccionados.

<%@ 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 == 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 - 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

Comentarios

El AddParsedSubObject método lo usa ASP.NET para agregar controles secundarios analizados al HtmlSelect control .

Se aplica a