We can do this by the help of "Delegates".
The situation is I have a user control with a dropdown in header.ascx file, which I have integrated in my masterpage.master.
Now I want to access the event of that dropdownbox (SelectedIndexChanged ) in my content page default2.aspx and the value of the drop down box.
How to do that ?
1. Create a Delegate and event Handler in your usercontrol.ascx.
//Creating delegate for dropdownlist
public delegate void OnSelectedIndex(object sender, EventArgs e);
public event OnSelectedIndex ddl_selectedIndexChanged;
2. Create a Delegate and Eventhandler in your Master page, which we will access in Content Page.
//Creating Delegates and Event handler
public delegate void MasterDropDown(object sender, EventArgs e);
public event MasterDropDown Header_DropDown;
3. Now access the same on content page
For this first call the master page like
<%@ MasterType VirtualPath="~/MasterPage.master"%>
//And then in your content page load method
protected void Page_Load(object sender, EventArgs e)
{
Master.Header_DropDown += new MasterPage.MasterDropDown(Master_Header_DropDown);
}
For Accessing the value
1. Define a property in ascx control//Geting the Drop Down Value
public string DropDownValue
{
get { return DropDownList1.SelectedValue; }
}
2. Access the value in master page
//Geting the User Control value
public string UserControlValue
{
get { return uc_usercontrol1.DropDownValue; }
}
3. Now access the value in Content page in a lable
Label1.Text =Label1.Text+" "+ Master.UserControlValue;
Complete Code
User Control
uc_usercontrol.ascx <%@ Control Language="C#" AutoEventWireup="true" CodeFile="uc_usercontrol.ascx.cs" Inherits="uc_Usercontrols" %> <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" onselectedindexchanged="DropDownList1_SelectedIndexChanged"> <asp:ListItem>1</asp:ListItem> <asp:ListItem>2</asp:ListItem> <asp:ListItem>3</asp:ListItem> <asp:ListItem>4</asp:ListItem> <asp:ListItem>5</asp:ListItem> <asp:ListItem>6</asp:ListItem> <asp:ListItem></asp:ListItem> </asp:DropDownList>uc_usercontrol.ascx.cs using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Configuration; using System.Collections.Specialized; public partial class uc_Usercontrols : System.Web.UI.UserControl { //Geting the Drop Down Value public string DropDownValue { get { return DropDownList1.SelectedValue; } }
//Creating delegate for dropdownlist public delegate void OnSelectedIndex(object sender, EventArgs e); public event OnSelectedIndex ddl_selectedIndexChanged; protected void Page_Load(object sender, EventArgs e) { }
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e) { this.ddl_selectedIndexChanged(sender, e);
} }
Master Page
MasterPage.master <%@ Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="MasterPage" %><%@ Register Src="uc_usercontrol.ascx" TagName="uc_usercontrol" TagPrefix="uc1" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> <asp:ContentPlaceHolder ID="head" runat="server"> </asp:ContentPlaceHolder> </head> <body> <form id="form1" runat="server"> <div> <uc1:uc_usercontrol ID="uc_usercontrol1" runat="server" /> <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server"> </asp:ContentPlaceHolder> </div> </form> </body> </html> MasterPage.master.cs
using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls;
public partial class MasterPage : System.Web.UI.MasterPage { //Geting the User Control value public string UserControlValue { get { return uc_usercontrol1.DropDownValue; } } //Creating Delegates and Event handler public delegate void MasterDropDown(object sender, EventArgs e); public event MasterDropDown Header_DropDown; protected void Page_Load(object sender, EventArgs e) { this.uc_usercontrol1.ddl_selectedIndexChanged += new uc_Usercontrols.OnSelectedIndex(uc_usercontrol1_ddl_selectedIndexChanged); }
void uc_usercontrol1_ddl_selectedIndexChanged(object sender, EventArgs e) { this.Header_DropDown(sender, e); } }
Default2.aspx <%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %> <%@ MasterType VirtualPath="~/MasterPage.master"%> <asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"> </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server"> <asp:Label ID="Label1" runat="server" Text="Hi I m visible now" Visible="false"></asp:Label> </asp:Content>
Default2.aspx.cs
using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls;
public partial class Default2 : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e) { Master.Header_DropDown += new MasterPage.MasterDropDown(Master_Header_DropDown); }
void Master_Header_DropDown(object sender, EventArgs e) { //Here you can do any activity on change dropdown list Label1.Visible = true; //Accessing the Master page User Control Value in content Page Label1.Text =Label1.Text+" "+ Master.UserControlValue; } }
