Question

I am constructing a c#/.net website.

The site uses master pages and update panels.

I have a situation where I have a usercontrol in the page, that needs to update a user control in the master page and vice versa.

I know how to construct a delegate between the usercontrol and the page, or usercontrol and master page, but i’m unsure about a couple of things as my knowledge of .net isn’t that great.

1) How to construct a delegate between usercontrol -> page -> master page (2 levels)
2) The same backwards usercontrol -> master page -> page

I’m not sure if any of the components of 1) and 2) could be shared. For instance a single delegate event that spans the 2 levels and works both ways.

I’d appreciate any advice/examples.

Thanks in advance.

Answer 1

I cannot be too sure from your question, but perhaps you need to know that you can declare the delegate at the namespace level?

namespace MyNamespace
{
   public delegate void MyDelegate(object sender, EventArgs e);

   public class MyClass
   {
      public event MyDelegate OnSomethingHappened;
   }
}

EDIT
I think I understand a bit better…see if this is what you are looking for:
This is the code from the ‘.cs’ files of a Site.Master page, and a WebUserControl…the delegate is declared globally in the namespace, within the master page, and the user control declares an event of that delegate type:

// MASTER PAGE
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication4
{
    public delegate void MyDelegate(object sender, EventArgs e);

    public partial class SiteMaster : System.Web.UI.MasterPage
    {
        // Here I am declaring the instance of the control...I have put it here to illustrate
        // but normally you have dropped it onto your form in the designer...
        protected WebUserControl1 ctrl1;

        protected void Page_Load(object sender, EventArgs e)
        {
            // instantiate user control...this is done automatically in the designer.cs page 
            // if you created it in the visual designer...
            this.ctrl1 = new WebUserControl1();

            // start listening for the event...
            this.ctrl1.OnSomethingHappened += new MyDelegate(ctrl1_OnSomethingHappened);
        }

        void ctrl1_OnSomethingHappened(object sender, EventArgs e)
        {
            // here you react to the event being fired...
            // perhaps you have "sent" yourself something as an object in the 'sender' parameter
            // or perhaps you have declared a delegate that uses your own custom EventArgs...
        }
    }
}

//WEB USER CONTROL
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication4
{
    public partial class WebUserControl1 : System.Web.UI.UserControl
    {
        public event MyDelegate OnSomethingHappened;

        protected void Page_Load(object sender, EventArgs e)
        {

        }

        private void MyMethod()
        {
            // do stuff...then fire event for some reason...
            // Incidentally, ALWAYS do the != null check on the event before
            // attempting to launch it...if nothing has subscribed to listen for the event
            // then attempting to reference it will cause a null reference exception.
            if (this.OnSomethingHappened != null) { this.OnSomethingHappened(this, EventArgs.Empty); }
        }
    }
}