Label.AddParsedSubObject(Object) Metoda

  • Odwołanie

Definicja

Przestrzeń nazw:
System.Web.UI.WebControls
Zestaw:
System.Web.dll

Powiadamia kontrolkę, że element został przeanalizowany i dodaje element do kontrolki 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)

Parametry

obj
Object

Obiekt reprezentujący przeanalizowany element.

Przykłady

W poniższym przykładzie kodu pokazano, jak zastąpić AddParsedSubObject metodę w niestandardowej Label kontrolce serwera, tak aby zawsze ustawiała właściwość text na właściwość tekstową przeanalizowanego obiektu, jeśli analizowany obiekt to Literal, a w przeciwnym razie pusty ciąg.

<%@ 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

Uwagi

Metoda AddParsedSubObject jest używana głównie przez deweloperów kontrolek podczas wyprowadzania niestandardowej kontrolki Label z klasy.

Jeśli obiekt wejściowy jest obiektem LiteralControl, a kontrolka Label nie ma kontrolek podrzędnych, obiekt wejściowy jest używany do ustawiania Text właściwości kontrolki Label . AddParsedSubObject W przeciwnym razie metoda klasy bazowej Control jest wywoływana, a określony obiekt jest dodawany do kolekcjiControls.

Dotyczy