How to update user control in UpdatePanel? - asp.net

Question

I want to refresh a user control in UpdatePanel, but I would also like to refresh it with different property values.
<asp:UpdatePanel runat=server ID=up1>
<Triggers>
<asp:AsyncPostBackTrigger controlid="but01" eventname="Click" />
</Triggers>
<ContentTemplate>
<asp:Button runat="server" Text="Test" ID="but01" />
<UC:Uc runat=server ID="Uc1" />
</ContentTemplate>
</asp:UpdatePanel>
Codebehind for but01 click is
void but01_Click(object sender, EventArgs e)
{
this.Uc1.ID = 1;
this.Uc1.Length = 50;
}
I tested this code, and the user control is being refreshed, but new values ID=1, Length=50 are not applied.
Control code behind is rather simple
namespace Admin.Web.Controls
{
public partial class Uc1 : System.Web.UI.UserControl
{
private string p_to;
private string p_from;
private string p_subject;
private string p_body;
private string p_priority;
}
protected void Page_Load(object sender, EventArgs e)
{
this.txtFrom.Text = p_from;
this.txtTo.Text = p_to;
this.txtSubject.Text = p_subject;
this.txtBody.Text = p_body;
}
public string Subject
{
get
{
return p_subject;
}
set
{
p_subject = value;
}
}
public string From
{
get
{
return p_from;
}
set
{
p_from = value;
}
}
public string To
{
get
{
return p_to;
}
set
{
p_to = value;
}
}
public string Body
{
get
{
return p_body;
}
set
{
p_body = value;
}
}
}
ascx header is
<%# Control Language="c#" Inherits="Admin.Web.Controls.Uc1" AutoEventWireup="true" Codebehind="Uc1.ascx.cs" %>
When I initiate user control from aspx page during page load, everything is ok. On postback from control panel, user control is refreshed (checked with Label + time), but no values are passed to user control.

Answer 1

Remove Triggers tag
http://msdn.microsoft.com/en-us/library/Bb399001(v=vs.100).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-2
OR
Move asp:Button to outside of UpdatePanel.
http://msdn.microsoft.com/en-us/library/Bb399001(v=vs.100).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-5
Update:
Please make the setter and getter of the control as -
public string Subject
{
get { return txtSubject.Text; }
set { txtSubject.Text = value; }
}