Checkboxes in usercontrol won't check although they say they are - asp.net

Question

I have a simple usercontrol, with a datalist, and checkboxes inside.
<asp:DataList ID="DataListDroits" runat="server" DataKeyField="droit_id" DataSourceID="SqlDroits">
<ItemTemplate>
<asp:HiddenField ID="HiddenFieldDroitID" runat="server" Value='<%# Eval("droit_id") %>' />
<asp:CheckBox ID="CheckBoxDroit" runat="server" Text='<%# Eval("droit_label") %>' />
</ItemTemplate>
</asp:DataList>
I check them using code behind in the usercontrol :
Public Sub CheckRole(ByVal role As Integer)
For Each dliOrganisme As DataListItem In Me.DataListOrganismes.Items
Dim DataListDroits As DataList = dliOrganisme.FindControl("DataListDroits")
If DataListDroits IsNot Nothing Then
For Each dliDroit As DataListItem In DataListDroits.Items
If role = CInt(CType(dliDroit.FindControl("HiddenFieldDroitID"), HiddenField).Value) Then
Dim CheckBoxDroit As CheckBox = dliDroit.FindControl("CheckBoxDroit")
CheckBoxDroit.Checked = True
End If
Next ' DataListDroits
End If
Next ' DataListItem
End Sub
And in the page_load of the calling webform :
Dim CheckBoxesRoles1 As ASP.organisme_checkboxesroles_ascx = Me.FormViewRubrique.FindControl("CheckBoxesRoles1")
Dim rolesCoches As New List(Of Integer)
Dim cmdRoles As New SqlCommand("SELECT droit_id FROM o_droit_rubrique WHERE rubrique_id = #rubrique", conn)
cmdRoles.Parameters.AddWithValue("rubrique", Request.QueryString("rid"))
Dim rdrRoles As SqlDataReader = cmdRoles.ExecuteReader
While rdrRoles.Read
CheckBoxesRoles1.CheckRole(rdrRoles("droit_id"))
End While
rdrRoles.Close()
... and yet, they are not checked.
But if I do this :
Protected Sub Page_LoadComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.LoadComplete
Dim CheckBoxesRoles1 As ASP.organisme_checkboxesroles_ascx = Me.FormViewRubrique.FindControl("CheckBoxesRoles1")
If CheckBoxesRoles1 IsNot Nothing Then
For Each role As Integer In CheckBoxesRoles1.CheckedRoles
Response.Write("role : " & role & "<br>")
Next
End If
End Sub
I tells me they are...
I'm going mad here ! Why does it tells me they are checked while they obviously are not ?

Answer 1

Well... for one thing, you aren't checking if your checkboxes are checked, all you're doing is outputting the value of "role". What exactly are you expecting here?
Two suggestions:
1) Set the Checked property of your CheckBox in the aspx like so:
<asp:CheckBox ID="CheckBoxDroit" runat="server" Text='<%# Eval("droit_label") %>' Checked='<%# (Eval("droit_id") > 0).ToString()' />
2) Set the property in OnItemDataBound in code-behind
One of two things is happening: Either the code you expect to be executing is not really executing (ie, is your if block ever true? Is the control not being found? Try a breakpoint), OR you are doing it at the wrong time -- after the page has already been rendered.