Why a control inside usercontrol is not accessible in .aspx page?
Question
I have created a user control with a radio button inside it. I have also created a public property of type radio button and assigned it that radio button so can be accessed in aspx pages code behind.
public partial class WebUserControl : System.Web.UI.UserControl
{
public RadioButton radiobtn { get; set; }
protected void Page_Load(object sender, EventArgs e)
{
initiateControls();
}
private void initiateControls()
{
radiobtn = RadioButton1;
}
}
now I have dragged that user control into .aspx page and tried accessing a radio button inside user control but is throws 'null reference exception'.
.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="test" %>
<%@ Register src="UserControls/WebUserControl.ascx" tagname="WebUserControl" tagprefix="uc1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<uc1:WebUserControl ID="WebUserControl1" runat="server" />
</div>
</form>
</body>
</html>
.cs
public partial class test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
try
{
WebUserControl1.radiobtn.Visible = false;
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
}
}
2 answers
solution1
1 2017-07-15 23:09:27
You should implement the get property:
public RadioButton radiobtn
{
get
{
return RadioButton1;
}
}
solution2
0 2017-07-15 22:48:17
You Page Page_Load runs before the control's Page_Load.
This page shows the order of events:
https://msdn.microsoft.com/en-us/library/ms178472.aspx
You could access the control in LoadComplete or PreRender, but not on Page_Load
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