Show/hide column in gridview based on Role - asp.net

Question

I have a GridView I populate, and want to show/hide the edit link based on whether the person logged in is either an Admin or User. I am not receiving any errors but cannot figure out why its not working.
aspx
<asp:GridView ID="RepView" runat="server" HeaderStyle-BackColor="#bfbfbf" HeaderStyle-ForeColor="White" HeaderStyle-Font-Underline="true" CellPadding="2" GridLines="None" AutoGenerateColumns="false" Width="990px">
<AlternatingRowStyle BackColor="#DCDCDC" />
<Columns>
<asp:BoundField DataField="Id" HeaderText="Id" />
<asp:BoundField DataField="FirstName" HeaderText="First Name" />
<asp:BoundField DataField="LastName" HeaderText="Last Name" />
<asp:BoundField DataField="EmployeeId" HeaderText="Employee Id" />
<asp:BoundField DataField="Shift" HeaderText="Shift" />
<asp:BoundField DataField="Supervisor" HeaderText="Supervisor" />
<asp:BoundField DataField="Center" HeaderText="Center" />
<asp:BoundField DataField="DateSubmitted" HeaderText="Date Entered" />
<asp:TemplateField ItemStyle-HorizontalAlign="Center" HeaderText="Details">
<ItemTemplate>
Edit
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
code behind
Private Sub BindGrid()
Dim DefaultConnection As String = ConfigurationManager.ConnectionStrings("DefaultConnection").ConnectionString
Using con As New SqlConnection(DefaultConnection)
'This is not working...
If My.User.IsInRole("User") Then
RepView.Columns(9).Visible = False
ElseIf My.User.IsInRole("Admin") Then
RepView.Columns(9).Visible = True
End If
' End of questionable part....
Using cmd As New SqlCommand()
cmd.CommandText = ("SELECT * from Reps")
cmd.Connection = con
con.Open()
RepView.DataSource = cmd.ExecuteReader()
RepView.DataBind()
con.Close()
End Using
End Using
End Sub

Answer 1

Try moving your code behind "Questionable Part" from the Private Sub BindGrid() to The gridview_Load event. My guess is that what's happening is that the gridview is loading, then it gets to your code Private sub BindGrid() to show/hide columns but the columns are already loaded, therefor it can not hide them. It will continue to show the columns even after running through this code unless you run the check and show/hide the columns in the load event.
One other possible solution is that it looks like in the Private Sub BindGrid() you are trying to hide the columns before the query which means the columns will not have been created yet so you have to create the columns first before you can hide and of them. Move the questionable part down below your sql command.
Try something like this...
Protected Sub GridView1_RowDataBound(sender As Object, e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
Dim x As Integer = 0
If x = 0 Then
GridView1.Columns(0).Visible = False
Else
GridView1.Columns(0).Visible = True
End If
End Sub
I have tested this and using x = 0 will hide the first column using x = 1 will show the first column.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataKeyNames="ID" DataSourceID="SqlDataSource1">
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:Sprayer_Parts_CatalogConnectionString %>"
SelectCommand="SELECT [ID], [Order#] AS column1, [Gallon], [Price] FROM [Tanks]">
</asp:SqlDataSource>