Хорошо, я нашел обходной путь, который не включает использование триггеров или реестра scriptManager.
Это страница
<%@ Page Title="Home Page" Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs"
Inherits="TestProject._Default" %>
<%@ Register TagPrefix="uc" TagName="A" Src="~/UserControls/ucA.ascx" %>
<html>
<head>
<title>Example</title>
</head>
<body>
<form id="Form1" action="Default.aspx" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="upMain" runat="server" ChildrenAsTriggers="false" UpdateMode="Conditional">
<ContentTemplate>
<div id="divContent" runat="server">
</div>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Button1" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="BtnClick" />
<asp:PlaceHolder ID="phMain" runat="server">
</asp:PlaceHolder>
</form>
</body>
</html>
Это код страницы
using System;
using System.Collections.Generic;
using System.Web.UI;
using System.Web.UI.WebControls;
using TestProject.UserControls;
namespace TestProject
{
public partial class _Default : Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
divContent.InnerHtml =
"<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero. Sed cursus ante" +
" dapibus diam. Sed nisi. Nulla quis sem at nibh elementum imperdiet. Duis sagittis ipsum. Praesent mauris. Fusce" +
" nec tellus sed augue semper porta. Mauris massa. Vestibulum lacinia arcu eget nulla. Class aptent taciti sociosqu" +
" ad litora torquent per conubia nostra, per inceptos himenaeos. Curabitur sodales ligula in libero. Sed dignissim" +
" lacinia nunc. </p>" +
"<p>Curabitur tortor. Pellentesque nibh. Aenean quam. In scelerisque sem at dolor. Maecenas mattis. Sed convallis" +
" tristique sem. Proin ut ligula vel nunc egestas porttitor. Morbi lectus risus, iaculis vel, suscipit quis, luctus" +
" non, massa. Fusce ac turpis quis ligula lacinia aliquet. Mauris ipsum. Nulla metus metus, ullamcorper vel, tincidunt" +
" sed, euismod in, nibh. Quisque volutpat condimentum velit. Class aptent taciti sociosqu ad litora torquent per conubia" +
" nostra, per inceptos himenaeos. </p>" +
"<p>Nam nec ante. Sed lacinia, urna non tincidunt mattis, tortor neque adipiscing diam, a cursus ipsum ante quis turpis." +
" Nulla facilisi. Ut fringilla. Suspendisse potenti. Nunc feugiat mi a tellus consequat imperdiet. Vestibulum sapien. Proin" +
" quam. Etiam ultrices. Suspendisse in justo eu magna luctus suscipit. Sed lectus. Integer euismod lacus luctus magna. Quisque" +
" cursus, metus vitae pharetra auctor, sem massa mattis sem, at interdum magna augue eget diam. Vestibulum ante ipsum primis in" +
" faucibus orci luctus et ultrices posuere cubilia Curae; Morbi lacinia molestie dui. </p>" +
"<p>Praesent blandit dolor. Sed non quam. In vel mi sit amet augue congue elementum. Morbi in ipsum sit amet pede facilisis" +
" laoreet. Donec lacus nunc, viverra nec, blandit vel, egestas et, augue. Vestibulum tincidunt malesuada tellus. Ut ultrices" +
" ultrices enim. Curabitur sit amet mauris. Morbi in dui quis est pulvinar ullamcorper. Nulla facilisi. Integer lacinia sollicitudin" +
" massa. Cras metus. </p>" +
"<p>Sed aliquet risus a tortor. Integer id quam. Morbi mi. Quisque nisl felis, venenatis tristique, dignissim in, ultrices sit amet," +
" augue. Proin sodales libero eget ante. Nulla quam. Aenean laoreet. Vestibulum nisi lectus, commodo ac, facilisis ac, ultricies eu," +
" pede. Ut orci risus, accumsan porttitor, cursus quis, aliquet eget, justo. Sed pretium blandit orci. Ut eu diam at pede suscipit" +
" sodales. Aenean lectus elit, fermentum non, convallis id, sagittis at, neque. Nullam mauris orci, aliquet et, iaculis et, viverra" +
" vitae, ligula. </p>";
//Clear session on first load
Session["controls"] = null;
}
if (Session["controls"] != null)
{
RenderControls(Session["controls"] as List<Control>);
var postbackInit = GetPostBackControl(this);
LbClick(postbackInit, null);
}
}
//Get Control that caused postback
public static Control GetPostBackControl(Page page)
{
Control control = null;
string ctrlname = page.Request.Params.Get("__EVENTTARGET");
if (!string.IsNullOrEmpty(ctrlname))
{
control = page.FindControl(ctrlname);
}
else
{
foreach (string ctl in page.Request.Form)
{
Control c = page.FindControl(ctl);
if (c is Button)
{
control = c;
break;
}
}
}
return control;
}
public void Partial_Postback(ucA sender)
{
var counter = 5;
var controls = new List<Control>();
sender.Key = counter;
sender.ID = counter.ToString();
controls.Add(sender);
Session["controls"] = controls;
RenderControls(controls);
sender.LbDetails.ID = counter.ToString();
}
private void RenderControls(List<Control> controls)
{
foreach (var control in controls)
{
var controlReference = Page.FindControl(control.ID);
if (controlReference == null)
{
divContent.Controls.Add(control);
}
}
upMain.Update();
}
private void LbClick(object sender, EventArgs e)
{
divContent.InnerHtml = string.Empty;
divContent.InnerText = string.Format("trigger works and ID = {0}", (sender as LinkButton).ID);
upMain.Update();
}
public void BtnClick(object sender, EventArgs e)
{
var controlA = new ucA();
controlA = (ucA)LoadControl("~/UserControls/ucA.ascx");
divContent.Controls.Add(controlA);
}
}
}
Это пользовательский элемент управления
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="ucA.ascx.cs" Inherits="TestProject.UserControls.ucA" %>
<asp:LinkButton ID="LinkButton1" runat="server" ToolTip="This is the tool tip">Click Me to Remove Text</asp:LinkButton>
Это код пользовательского элемента управления
using System;
using System.Reflection;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace TestProject.UserControls
{
public partial class ucA : UserControl
{
public int Key;
public LinkButton LbDetails
{
get { return this.LinkButton1; }
set { LinkButton1 = value; }
}
protected void Page_Load(object sender, EventArgs e)
{
Page.GetType().InvokeMember("Partial_Postback", BindingFlags.InvokeMethod, null, Page, new object[] { this });
}
}
}