Datagrid with footer sums - hide the column if zero

I have a datagrid where I am summing values in the ItemDataBound as I go along. Then, in the footer, I enter this sum. e.g:
<asp:TemplateColumn HeaderText="Issues"> <ItemTemplate><%# IIf(IsIssuesDefected(DataBinder.Eval(Container.DataItem, "Issues"), 2), DataBinder.Eval(Container.DataItem, "lvservice_vHorizontalClearanceIssues"), "")%> </ItemTemplate> <FooterTemplate><%# IssuesDefectedCount %></FooterTemplate> </asp:TemplateColumn> So basically, I only display the value in the cell if it is an issue, and then place the sum of the issues at the bottom. I have a lot of columns like this.
What I require next is to hide the columns if the sum is zero. However, the following code does not work:
Private Sub HideColumnsWithNoDefects() Dim columnIndex As Integer = 0 While columnI ...