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Label.AddParsedSubObject-Methode

Benachrichtigt das Steuerelement, dass ein Element analysiert wurde, und fügt das Element dem Label-Steuerelement hinzu.

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

Syntax

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

Me.AddParsedSubObject(obj)
protected override void AddParsedSubObject (
    Object obj
)
protected:
virtual void AddParsedSubObject (
    Object^ obj
) override
protected void AddParsedSubObject (
    Object obj
)
protected override function AddParsedSubObject (
    obj : Object
)

Parameter

  • obj
    Ein Objekt, das das analysierte Element darstellt.

Hinweise

Die AddParsedSubObject-Methode wird hauptsächlich von Steuerelemententwicklern beim Ableiten eines benutzerdefinierten Steuerelements von der Label-Klasse verwendet.

Wenn es sich bei dem Eingabeobjekt um ein LiteralControl handelt und das Label-Steuerelement keine untergeordneten Steuerelemente besitzt, wird das Eingabeobjekt verwendet, um die Text-Eigenschaft des Label-Steuerelements festzulegen. Andernfalls wird die AddParsedSubObject-Methode der Control-Basisklasse aufgerufen, und das angegebene Objekt wird der Controls-Auflistung hinzugefügt.

Beispiel

Im folgenden Codebeispiel wird veranschaulicht, wie Sie die AddParsedSubObject-Methode in einem benutzerdefinierten Label-Serversteuerelement überschreiben können, sodass es die Texteigenschaft auf die Texteigenschaft des analysierten Objekts festlegt, sofern es sich bei dem analysierten Objekt um ein Literal handelt. Andernfalls wird eine leere Zeichenfolge festgelegt.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom Label - AddParsedSubObject - VB.NET Example</title>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom Label - AddParsedSubObject - VB.NET Example</h3>
            
            <aspSample:CustomLabelAddParsedSubObject id="Label1" runat="server" 
             ToolTip="Microsoft Corp.">Microsoft Corp.</aspSample:CustomLabelAddParsedSubObject>

        </form>
    </body>
</HTML>

...
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomLabelAddParsedSubObject
        Inherits System.Web.UI.WebControls.Label

        Protected Overrides Sub AddParsedSubObject(ByVal obj As Object)

            ' If the server control contains any child controls.
            If Me.HasControls() Then

                ' Notify the base server control that an element, either XML or HTML, 
                ' was parsed, and adds the element to the server control's 
                ' ControlCollection object.
                MyBase.AddParsedSubObject(obj)
                ' Else the server control doesn't contain any child controls.
            Else
                ' If the parsed element is a LiteralControl.
                If TypeOf obj Is System.Web.UI.LiteralControl Then

                    ' Set the server control's Text property to the parsed element's Text value.
                    Me.Text = CType(obj, System.Web.UI.LiteralControl).Text

                    ' Else the parsed element is not a LiteralControl.
                Else
                    ' If the server control has a value in the the Text property.
                    Dim currentText As String = Me.Text
                    If currentText.Length <> 0 Then

                        ' Set the server control's Text property to an empty string.
                        Me.Text = System.String.Empty

                        ' Notify the base server control that a new LiteralControl was parsed, 
                        ' and adds the element to the server control's ControlCollection object.
                        MyBase.AddParsedSubObject(New System.Web.UI.LiteralControl(currentText))
                    End If
                    MyBase.AddParsedSubObject(obj)
                End If
            End If
        End Sub
    End Class
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom Label - AddParsedSubObject - C# Example</title>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom Label - AddParsedSubObject - C# Example</h3>
            
            <aspSample:CustomLabelAddParsedSubObject 
              id="Label1" runat="server" 
              ToolTip="Microsoft Corp.">Microsoft Corp.</aspSample:CustomLabelAddParsedSubObject>

        </form>
    </body>
</HTML>

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

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomLabelAddParsedSubObject : System.Web.UI.WebControls.Label
  {
    protected override void AddParsedSubObject(object obj)
    {
      // If the server control contains any child controls.
      if (this.HasControls()) 
      {
        // Notify the base server control that an element, either XML or HTML, 
        // was parsed, and adds the element to the server control's 
        // ControlCollection object.
        base.AddParsedSubObject(obj);
      }
        // Else the server control doesn't contain any child controls.
      else 
      {
        // If the parsed element is a LiteralControl.
        if (obj is System.Web.UI.LiteralControl) 
        {
          // Set the server control's Text property to the parsed element's Text value.
          this.Text = ((System.Web.UI.LiteralControl)obj).Text;
        }
          // Else the parsed element is not a LiteralControl.
        else 
        {
          // If the server control has a value in the the Text property.
          string currentText = this.Text;
          if (currentText.Length != 0) 
          {
            // Set the server control's Text property to an empty string.
            this.Text = System.String.Empty;

            // Notify the base server control that a new LiteralControl was parsed, 
            // and adds the element to the server control's ControlCollection object.
            base.AddParsedSubObject(new System.Web.UI.LiteralControl(currentText));
          }
          base.AddParsedSubObject(obj);
        }
      }
    }
  }
}
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom Label - AddParsedSubObject - VJ# Example</title>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom Label - AddParsedSubObject - VJ# Example</h3>
            
            <aspSample:CustomLabelAddParsedSubObject 
              id="Label1" runat="server" 
              ToolTip="Microsoft Corp.">Microsoft Corp.</aspSample:CustomLabelAddParsedSubObject>

        </form>
    </body>
</HTML>

...
package Samples.AspNet.JSL.Controls; 

public class CustomLabelAddParsedSubObject
    extends System.Web.UI.WebControls.Label
{
    protected void AddParsedSubObject(Object obj)
    {
        // If the server control contains any child controls.
        if (this.HasControls()) {
            // Notify the base server control that an element, 
            // either XML or HTML, was parsed, and adds the element 
            // to the server control's ControlCollection object.
            super.AddParsedSubObject(obj);
        }
        // Else the server control doesn't contain any child controls.
        else {
            // If the parsed element is a LiteralControl.
            if (obj instanceof System.Web.UI.LiteralControl) {
                // Set the server control's Text property to the parsed 
                // element's Text value.
                this.set_Text(((System.Web.UI.LiteralControl)obj).get_Text());
            }
            // Else the parsed element is not a LiteralControl.
            else {
                // If the server control has a value in the the Text property.
                String currentText = this.get_Text();
                if (currentText.get_Length() != 0) {
                    // Set the server control's Text property to an empty 
                    // string.
                    this.set_Text("");
                    // Notify the base server control that a new 
                    // LiteralControl was parsed, and adds the element to 
                    // the server control's ControlCollection object.
                    super.AddParsedSubObject(new System.Web.UI.
                        LiteralControl(currentText));
                }
                super.AddParsedSubObject(obj);
            }
        }
    } //AddParsedSubObject
} //CustomLabelAddParsedSubObject

Plattformen

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

Label-Klasse
Label-Member
System.Web.UI.WebControls-Namespace

Weitere Ressourcen

Label-Webserver-Steuerelement
Gewusst wie: Schutz gegen Skriptangriffe in einer Webanwendung durch Anwenden von HTML-Codierung auf Zeichenfolgen