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.