HtmlSelect.AddParsedSubObject(Object) Method
Definition
Important
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Adds a parsed child control to the HtmlSelect control.
protected:
override void AddParsedSubObject(System::Object ^ obj);protected override void AddParsedSubObject (object obj);override this.AddParsedSubObject : obj -> unitProtected Overrides Sub AddParsedSubObject (obj As Object)Parameters
- obj
- Object
The parsed child control to add.
Implements
Exceptions
The child control specified by the obj parameter must be of the type ListItem.
Examples
The following code example demonstrates how to override the AddParsedSubObject method in a custom server control so that it always checks that an instance of the ListItem class is added to the HtmlSelect selected items collection.
<%@ 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
Remarks
The AddParsedSubObject method is used by ASP.NET to add parsed child controls to the HtmlSelect control.
Applies to
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