Label.AddParsedSubObject メソッドとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

Label.AddParsedSubObject メソッド

要素が解析されたことをコントロールに通知し、その要素を Label コントロールに追加します。

名前空間: System.Web.UI.WebControls
アセンブリ: System.Web (system.web.dll 内)
構文

Visual Basic (宣言)

Protected Overrides Sub
 AddParsedSubObject ( _
    obj As Object _
)

Visual Basic (使用法)

Dim obj As Object

Me.AddParsedSubObject(obj)

protected override void AddParsedSubObject
 (
    Object obj
)

C++

protected:
virtual void AddParsedSubObject (
    Object^ obj
) override

protected void AddParsedSubObject (
    Object obj
)

JScript

protected override function AddParsedSubObject
 (
    obj : Object
)

パラメータ

obj: 解析された要素を表すオブジェクト。

解説

AddParsedSubObject メソッドは、カスタムコントロールを Label クラスから派生させる場合に、主にコントロールの開発者によって使用されます。

入力オブジェクトが LiteralControl であり、Label コントロールに子コントロールがない場合、その入力オブジェクトを使用して Label コントロールの Text プロパティが設定されます。それ以外の場合は、基本クラス Control の AddParsedSubObject メソッドが呼び出され、指定したオブジェクトが Controls コレクションに追加されます。

使用例

カスタム Label サーバーコントロールの AddParsedSubObject メソッドをオーバーライドして、解析されるオブジェクトが Literal の場合は、常にテキストプロパティを解析されるオブジェクトのテキストプロパティに設定し、それ以外の場合は空の文字列に設定する方法を次のコード例に示します。

Visual Basic

<%@ 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>
<br /><span space="preserve">...</span><br
 />    <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>
<br /><span space="preserve">...</span><br />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>
<br /><span space="preserve">...</span><br />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