Accessing object in parent user control from child user control

Question

So I have a user control, Parent.ascx:

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="Parent.ascx.cs" 
    Inherits="Parent" %>
<%@ Register TagPrefix="cc" TagName="Child" Src="~/Child.ascx" %>

<asp:HiddenField ID="hfId" runat="server" />

<cc:Child ID="child1" runat="server" />

My child control Child.ascx contains a button, and in the code-behind I'd like to access the value of the hidden field hfId in the click event of that button

I can't use a user control attribute and set it on Page_Load because the value of that hidden field is changing through jQuery events in the Parent.ascx control

Answer 1

Use the below code to access the hidden field from the child control. this.Parent will give the parent control & use FindControl to find the control by ID.

HiddenField hfID = this.Parent.FindControl("hfId") as HiddenField;
string hiddenvalue = hfID.Value;

If you change the value of the hidden field on page load, then on button click, the updated value gets reflected.

Answer 2

您可以使用以下方式访问孩子的控件：

var hfId = (HiddenField)NamingContainer.FindControl("hfId");