Question

I have a UserControl which I have added to my web.config

<add tagPrefix="BCF" src="~/controls/MyMessageBox.ascx" tagName="error"/>

and added to my master page

<BCF:error ID="BCError" runat="server" Visible="false" />

Now I need to be able to reference this control AND its public properties from all child pages that use that masterpage. I did this is my BasePage OnLoad event

public UserControl BCError;
BCError = (UserControl)Master.FindControl("BCError");

Problem is, although I can do this in the .aspx page

BCError.Visible = true;

I cannot reference any of the Controls properties I have put in? Such as ShowError .. If I do

BCError.ShowError = "Error Message";

I just get an error saying

‘System.Web.UI.UserControl’ does not contain a definition for ‘ShowInfo’ and no extension method ‘ShowInfo’

Can you please point me in the right direction!

This is the code for the user control… I can use the properties in the masterpage code behind (And in a page if I put the control directly into it) but cannot use them in the child page code behind?? It doesn’t even show the properties or wrapper methods in the intellisense?

    using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class MyMessageBox : System.Web.UI.UserControl
{
    #region Properties
    public bool ShowCloseButton { get; set; }

    #endregion

    #region Load
    protected void Page_Load(object sender, EventArgs e)
    {
        if (ShowCloseButton)
            CloseButton.Attributes.Add("onclick", "document.getElementById('" + MessageBox.ClientID + "').style.display = 'none'");
    }
    #endregion

    #region Wrapper methods
    public void ShowError(string message)
    {
        Show(MessageType.Error, message);
    }

    public void ShowInfo(string message)
    {
        Show(MessageType.Info, message);
    }

    public void ShowSuccess(string message)
    {
        Show(MessageType.Success, message);
    }

    public void ShowWarning(string message)
    {
        Show(MessageType.Warning, message);
    } 
    #endregion

    #region Show control
    public void Show(MessageType messageType, string message)
    {
        CloseButton.Visible = ShowCloseButton;
        litMessage.Text = message;

        MessageBox.CssClass = messageType.ToString().ToLower();
        this.Visible = true;
    } 
    #endregion

    #region Enum
    public enum MessageType
    {
        Error = 1,
        Info = 2,
        Success = 3,
        Warning = 4
    } 
    #endregion
}

Answer 1

Ok I think I reproduced roughly what your describing and I deleted my original answer cause it was way off.

What I found is that when you want a content page to reference a user control being used in a master page and the control is accesible and what not, you will get an error indicating that you need to reference a specific assembly, and then you get errors indicating that no Method exists of type such and such.

By adding the Register page directive on the child page to the user control resolved this issue. I reproduced this even with the control defined in the web.config or on the page. In both cases I still had to explicitly add a Register on the content page.

This doesn’t make sense to me but it allowed my code to compile and work. Give it a shot let me know.

Once you do this you can reference the control like

this.Master.MessageBox.ShowInfo();

This assumes that you have a public property called MessageBox on the Master Page.

Edit

I’ve also found that this works much better if you register the control on both the master and the content page and not use the web.config.

Edit

If you don’t want your child page to reference the user control your other option is expose methods on the master page like ShowInfo() which would delegate to the user control.