IAttributeAccessor インターフェイス

定義

public interface class IAttributeAccessor

public interface IAttributeAccessor

type IAttributeAccessor = interface

Public Interface IAttributeAccessor

派生

System.Web.DynamicData.DynamicControl

System.Web.DynamicData.DynamicField

System.Web.DynamicData.DynamicHyperLink

System.Web.UI.HtmlControls.HtmlControl

System.Web.UI.MobileControls.DeviceSpecificChoice

その他…

例

// The following class creates a custom ASP.NET server control that implements
// the IAttributeAccessor interface. It creates a MyTextBox class that contains
// Width and Text properties that get and set their values from view state.
// Pages that use this control create an instance of this control and set the
// Width property using the IAttributeAccessor.SetAttribute method. 
// The page then displays the values of the Text and Width properties 
// using the IAttributeAccessor.GetAttribute method.
// When compiled, this assembly is named MyAttributeAccessor.
using System;
using System.Web;
using System.Web.UI;
using System.Security.Permissions;

namespace AttributeAccessor
{
   [AspNetHostingPermission(SecurityAction.Demand, 
      Level=AspNetHostingPermissionLevel.Minimal)]
   public sealed class MyTextBox : Control, IAttributeAccessor
   {
      // Declare the Width property.
      public String Width
      {
         get
         {
            return (String)ViewState["Width"];
         }
         set
         {
            ViewState["Width"] = value;
         }
      }

      // Declare the Text property.
      public String Text
      {
         get
         {
            return (String)ViewState["Text"];
         }
         set
         {
            ViewState["Text"] = value;
         }
      }
      // Implement the SetAttribute method for the control. When
      // this method is called from a page, the control's properties
      // are set to values defined in the page.
      public void SetAttribute(String name, String value1)
      {
         ViewState[name] = value1;
      }

      // Implement the GetAttribute method for the control. When
      // this method is called from a page, the values for the control's
      // properties can be displayed in the page.
      public String GetAttribute(String name)
      {
         return (String)ViewState[name];
      }

      protected override void Render(HtmlTextWriter output)
      {
         output.Write("<input type=text id= " + this.UniqueID);
         output.Write(" Value='" + this.Text);
         output.Write("' Size=" + this.Width + ">");
      }
   }
}

' The following class creates a custom ASP.NET server control that implements
' the IAttributeAccessor interface. It creates a MyTextBox class that contains
' Width and Text properties that get and set their values from view state.
' Pages that use this control create an instance of this control and set the
' Width property using the IAttributeAccessor.SetAttribute method. 
' The page then displays the values of the Text and Width properties 
' using the IAttributeAccessor.GetAttribute method.
' When compiled, this assembly is named MyAttributeAccessor.
Imports System.Web
Imports System.Web.UI
Imports System.Security.Permissions

Namespace AttributeAccessor

 <AspNetHostingPermission(SecurityAction.Demand, _
   Level:=AspNetHostingPermissionLevel.Minimal)> _
 Public NotInheritable Class MyTextBox
   Inherits Control
   Implements IAttributeAccessor 

   ' Declare the Width property.   
   Public Property Width() As String
      Get
         Return CType(ViewState("Width"), String)
      End Get
      Set
         ViewState("Width") = value
      End Set
   End Property
   
   ' Declare the Text property.
   
   Public Property Text() As String
      Get
         Return CType(ViewState("Text"), String)
      End Get
      Set
         ViewState("Text") = value
      End Set
   End Property
   
   ' Implement the SetAttribute method for the control. When
   ' this method is called from a page, the control's properties
   ' are set to values defined in the page.
   Public Sub SetAttribute(name As String, value1 As String) Implements IAttributeAccessor.SetAttribute
      ViewState(name) = value1
   End Sub
   
   ' Implement the GetAttribute method for the control. When
   ' this method is called from a page, the values for the control's
   ' properties can be displayed in the page.
   Public Function GetAttribute(name As String) As String Implements IAttributeAccessor.GetAttribute
      Return CType(ViewState(name), String)
   End Function 'GetAttribute
   
   Protected Overrides Sub Render(output As HtmlTextWriter)
      output.Write(("<input type=text id= " + Me.UniqueID))
      output.Write((" Value='" + Me.Text))
      output.Write(("' Size=" + Me.Width + ">"))
   End Sub
 End Class
End Namespace 'AttributeAccessor

注釈

、、または ListItem クラスから継承するカスタム サーバー コントロールをWebControlHtmlControl作成すると、これらの各クラスで インターフェイスが実装されるため、.NET Framework によって属性へのプログラムによるアクセスが自動的にIAttributeAccessor提供されます。

これらのクラスの 1 つから継承されないカスタム サーバー コントロールを作成し、コントロールの厳密に型指定されたプロパティに対応しない属性へのプログラムによるアクセスを許可する場合は、必ず インターフェイスを IAttributeAccessor 実装してください。

メソッド

適用対象

こちらもご覧ください

• HtmlControl
• WebControl