Label.AddParsedSubObject(Object) Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Notifica al controllo che è stato analizzato un elemento e aggiunge l'elemento al controllo Label.

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)

Parametri

obj
Object

Oggetto che rappresenta l'elemento sottoposto ad analisi.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del AddParsedSubObject metodo in un controllo server personalizzato Label in modo che imposti sempre la proprietà text sulla proprietà text dell'oggetto analizzato, se l'oggetto analizzato è un Literaloggetto e su una stringa vuota in caso contrario.

<%@ 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 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>

<%@ 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 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>

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 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);
        }
      }
    }
  }
}

<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 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

Commenti

Il AddParsedSubObject metodo viene usato principalmente dagli sviluppatori di controlli durante la Label derivazione di un controllo personalizzato dalla classe .

Se l'oggetto di input è un LiteralControloggetto e il Label controllo non dispone di controlli figlio, l'oggetto di input viene utilizzato per impostare la Text proprietà del Label controllo. In caso contrario, viene chiamato il AddParsedSubObject metodo della classe di base Control e l'oggetto specificato viene aggiunto all'insieme Controls .

Si applica a