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TextBox.AddParsedSubObject Method

This API supports the .NET Framework infrastructure and is not intended to be used directly from your code.

Overridden to allow only literal controls to be added as the Text property.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

'Declaration
Protected Overrides Sub AddParsedSubObject ( _
	obj As Object _
)

Parameters

obj
Type: System.Object

An Object that represents the parsed element.

ExceptionCondition
HttpException

obj is not of type LiteralControl.

The following code example demonstrates how to override the AddParsedSubObject method in a custom server control so that it always sets the Text property to the parsed object's Text property if the parsed object is a Literal control, and throws an exception otherwise.

Security noteSecurity Note

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

<%@ 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 TextBox - AddParsedSubObject - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom TextBox - AddParsedSubObject - VB.NET Example</h3>

            <aspSample:CustomTextBoxAddParsedSubObject id="TextBox1" 
             runat="server">Hello World!</aspSample:CustomTextBoxAddParsedSubObject>
        </form>
    </body>
</html>
Imports System.Web
Imports System.Security.Permissions

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

        Protected Overrides Sub AddParsedSubObject(ByVal obj As Object)

            ' If the object is a LiteralControl, then set this control's Text property. 
            If TypeOf obj Is System.Web.UI.LiteralControl Then 
                Me.Text = CType(obj, System.Web.UI.LiteralControl).Text
            Else 
                Throw New System.Web.HttpException("You cannot have children controls of type " + obj.GetType().Name.ToString())
            End If 
        End Sub 
    End Class 
End Namespace

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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