Visual Studio .NET - How do you hide a datagrid column dynamically?

Hi, I only want to display a datagrid column under certain conditions.

I wrote the code below, but i got back an "error creating control".

<asp:datagrid id="dtgDetails" AutoGenerateColumns="False" Runat="server">
 <Columns>
<asp:BoundColumn Headertext="Compo" DataField="compo_desc"></asp:BoundColumn>
					
<% if boolGrid = 1 then %>
<asp:BoundColumn Headertext="Grade" DataField="grade_desc"></asp:BoundColumn>
<% end if %>

</Columns>
</asp:datagrid>

I defined boolGrid as a booleanvalue in the code behind.

Would appreciate your help.

Thanks,

Burak

Hi Burak,

To make a datagrid column hidden under certain conditions, you can set the Visible property of the datagrid column to False.

Hope this helps.

<asp:BoundColumn Headertext="Grade" DataField="grade_desc" Visible="<=%boolGrid %>"></asp:BoundColumn>

Ronald,

I have 2 tables with the same fields and 1 table with one additional field. I am writing a user control to query these tables and tie the dataset to the datagrid. I am passing in the table name to a stored procedure.

I want the extra datagrid column to only show up if I query the table with the extra field.

Let me work on hidign the column from the code behind and see how that goes.

Thanks,

Burak

if i write this 
<asp:BoundColumn Headertext="Grade" DataField="grade_desc" 
Visible="<%=boolGrid %>"></asp:BoundColumn> 

i get a control creation error.

if i write the folloiwng, i don't get any creation errors

<asp:BoundColumn Headertext="Grade" DataField="grade_desc" 
Visible="<%#boolGrid %>"></asp:BoundColumn> 

but when i run it, i get 
'DataBinding' is not an event of 'System.Web.UI.WebControls.BoundColumn'

if the datagrid column is expecting a datavalue and if the dataset does not contain that value, then you get an error when you bind it.

<asp:TemplateColumn HeaderText="Grade">
  <ItemTemplate>
	<asp:Label ID="lbl" Runat="server">
   <%# Container.DataItem("grade_desc") %>
 </asp:Label>
 </ItemTemplate>
</asp:TemplateColumn>

which means i can only use the user control for the 2 tables with the same fields and not for the one table that has 1 extra field.

if you have any ideas let me know.

Hi Burak,

One option that I can think of to avoid this problem is to return the missing column in the second table and just use NULL as its value.  This should solve the problem with the data binding.  Then after databinding, check if it's from the second table, then hide the column.

Hope this helps.

ronald,

i put this code in the grid

<asp:TemplateColumn HeaderText="Grade">
  <ItemTemplate>
      <asp:Label ID="lbl" Runat="server">
	<%  if boolGrid = "true" then %>
	  Container.DataItem("grade_desc") 
	<% else %>
 	 Container.DataItem("compo_desc") 
	<% end if %>
   </asp:Label>
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>

and then tweaked it in the code behind like this

 Dim strCnn, strSql As String
        strCnn = ConfigurationSettings.AppSettings("ConnectionString")
        Dim cnn As New SqlConnection(strCnn)

        Dim cmd As New SqlCommand
        cmd.Connection = cnn
        With cmd
       .CommandType = CommandType.StoredProcedure
       .Parameters.Add(New SqlParameter("@COMPO", SqlDbType.Char, 1)).Value =  ""
       End With

        If boolGrid = False Then
            cmd.Parameters.Add(New SqlParameter("@TABLE", SqlDbType.VarChar, 30)).Value = "Audit_Crs_grad"
            cmd.CommandText = "Audit_IdenticalTablesSearch"
        Else
            cmd.Parameters.Add(New SqlParameter("@GRADE", SqlDbType.Char, 3)).Value = ""
            cmd.CommandText = "Audit_TRV_ALLT_Search"
        End If


        Dim ds As New DataSet
        Dim cmdAdapter As New SqlDataAdapter(cmd)
        cmdAdapter.Fill(ds, "Results")

        If boolGrid = False Then
            dtgDetails.Columns(1).Visible = False
        End If
        dtgDetails.DataSource = ds.Tables("Results")
        dtgDetails.DataBind()


and it worked for me.