RadAjax for ASP.NET AJAX

When your application is running in Medium trust and you want to use RadAjax on your pages, you need to use one of the following approaches in order to make RadAjax work properly:

1. Inherit your page from RadAjaxPage as shown below:
   • C#
   • VB.NET

   CopyC#

   public partial class MyPage: System.We.UI.Page {}
   //should be changed to:
   public partial class MyPage: Telerik.Web.UI.RadAjaxPage {}

   CopyVB.NET

   Partial Public Class MyPage
       Inherits System.We.UI.Page
   End Class
   'should be changed to:
   Partial Public Class MyPage
       Inherits Telerik.Web.UI.RadAjaxPage
   End Class

2. Set the RestoreOriginalDelegate property of the RadAjax control to false:
   CopyASPX

   <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server" RestoreOriginalRenderDelegate="false">
   </telerik:RadAjaxManager>
   <telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server" RestoreOriginalRenderDelegate="false">
   </telerik:RadAjaxPanel>

3. Implement the IRadAjaxPage interface:
   • C#
   • VB.NET

   CopyC#

   public class MyPage : System.Web.UI.Page, Telerik.Web.UI.IRadAjaxPage
   {
       private System.Web.UI.RenderMethod _onRenderDelegate;
       #region IRadAjaxPage Members
       public void AttachOnRender(System.Web.UI.RenderMethod renderMethod)
       {
           _onRenderDelegate = renderMethod;
       }
       #endregion
       protected override void Render(System.Web.UI.HtmlTextWriter writer)
       {
           if (_onRenderDelegate != null)
           {
               _onRenderDelegate(writer, this);
           }
           base.Render(writer);
       }
   }

   CopyVB.NET

   Public Class MyPage
       Inherits System.Web.UI.Page
       Implements Telerik.Web.UI.IRadAjaxPage
       Private _onRenderDelegate As System.Web.UI.RenderMethod
   
       Public Sub AttachOnRender(ByVal renderMethod As System.Web.UI.RenderMethod)
           _onRenderDelegate = renderMethod
       End Sub
   
       Protected Overloads Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
           If Not _onRenderDelegate Is Nothing Then
               _onRenderDelegate(writer, Me)
           End If
           MyBase.Render(writer)
       End Sub
   End Class

Note that in all cases when the application is running in Medium trust you could have only one RadAjax control in the whole page hierarchy. Therefore in complex Master/Content Page applications we suggest using single RadAjaxManager on the Master page which could handle all available Ajax scenarios. The mentioned limitation is due to the fact that in Medium Trust the reflection permissions are not granted.