How to enable/disable web elements of a parent aspx page from the child ascx page?

Question

I have an aspx page with three web controls: one to control the List Users page, one to control the Edit Users page, and one to control the Add User page. I have discovered a method for accessing these elements, but it seems to be limited. Here is what I have done:

Protected Sub editUser(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs)
        'set selected user from gridview.
        Dim index As Integer = e.NewEditIndex
        Dim userId As Integer = gvListUsers.DataKeys(index).Value
        Session.Item("SelectedUserId") = userId

        'show edit page, hide list and add page.
        With Page.Form.Controls(1)
            .Controls(getControlId("loadAddUser")).Visible = False
            .Controls(getControlId("loadEditUser")).Visible = True
            .Controls(getControlId("loadListUser")).Visible = False
        End With
    End Sub

The getControlId function looks like this:

Public Function getControlId(ByVal control As String) As Integer
        Dim enumer As System.Collections.IEnumerator = Page.Form.Controls.Item(1).Controls.GetEnumerator
        Dim i As Integer

        For i = 0 To (Page.Form.Controls.Item(1).Controls.Count - 1)
            If Page.Form.Controls(1).Controls.Item(i).ID = control Then
                Return i
            End If
        Next
        Return Nothing
    End Function

This works in most cases. However, I am unable to access the "enabled" attribute of these web controls. Why is this, and how might I access that attribute?

Thanks :)

Answer 1

You could raise events from your UserControls which you subscribe to in the parent ASPX page. In the parent page event action you could enable/disable your controls,

Here's an example of events in UserControls: http://codebetter.com/blogs/brendan.tompkins/archive/2004/10/06/Easily-Raise-Events-From-ASP.NET-ASCX-User-Controls.aspx

Something else to think about: are you getting any benefit from moving this code into usercontrols? Would any of the individual controls be re-usable on their own? Creating tightly coupled controls that rely on each other being present doesn't give you much re-usability of the individual controls.

Answer 2

Visible is a property provided by the System.Web.UI.Control class, which is why you can access it directly. Enabled is not a property on this class, so you need to map the control object to a variable of the type of your custom control class if you want to access the Enabled property.

Dim myControl As TheAddUserControl

With Page.Form.Controls(1)    
  myControl = .Controls(getControlId("loadAddUser"))
  myControl.Enabled = False            
  .Controls(getControlId("loadEditUser")).Visible = True            
  .Controls(getControlId("loadListUser")).Visible = False        
End With

To expose an Enabled property in you user control:

Public Property Enabled As Boolean
    Get
     Return (Child1.Enabled And Child2.Enabled And Child3.Enabled)
    End Get
    Set(ByVal value As Boolean)
     Child1.Enabled = value
     Child2.Enabled = value
     Child3.Enabled = value
    End Set
End Poperty