Dynamically Created Gridview with Button in footer template

[joss Perold]

Hi

I have created a gridview dynamically from scratch and added it to my aspx page. This works fine, but i have a button in the footer of on of the columns, which when clicked on makes the gridview disappear and doesn't fire the onclick event that it should. This should obviously not be the case. My question is why does the event not fire and why does the gridview vanish?

Bear in mind i have never created aa gridview in the code behind before, so excuse me if i am being dense

Code creating columns

   Dim gvTownships As New GridView
            'COLUMNS
            Dim tmpCategory As New TemplateField
            tmpCategory.ItemTemplate = New cGridViewTemplate(DataControlRowType.DataRow, "Category")
            tmpCategory.HeaderTemplate = New cGridViewTemplate(DataControlRowType.Header, "Category")
            tmpCategory.FooterTemplate = New cGridViewTemplate(DataControlRowType.Footer, "Calculation")
   'INFORMATION
            gvTownships.AutoGenerateColumns = False
            gvTownships.ID = cmbChoice.SelectedItem.Text
            gvTownships.ShowFooter = True
            gvTownships.CssClass = "mGrid"
            gvTownships.RowStyle.Wrap = False
            gvTownships.HeaderStyle.CssClass = "mgrid"
            gvTownships.HeaderStyle.Wrap = True
            gvTownships.FooterStyle.CssClass = "mGridtf"
            gvTownships.AlternatingRowStyle.CssClass = "alt"
            gvTownships.GridLines = GridLines.Both
 
            'add columns
            gvTownships.Columns.Add(tmpCategory)
 
  gvTownships.DataSource = dstSuburbTowhShip
                gvTownships.DataBind()
 

Code to add button to footer

 
Sub InstantiateIn(ByVal container As System.Web.UI.Control) _
          Implements ITemplate.InstantiateIn
 
                Case DataControlRowType.Footer
                    If columnName = "Calculation" Then
                        Dim btnCalculate As New Button
                        btnCalculate.Text = "Calculate"
                        btnCalculate.CssClass = "button"
 
                        'add handler
                        AddHandler btnCalculate.Click, AddressOf btnCalculate_Clicked
                        container.Controls.Add(btnCalculate)
 
                    End If
 
                Case Else
 
                    ' Insert code to handle unexpected values. 
 
            End Select
 
        End Sub
     Private Sub btnCalculate_Clicked(ByVal sender As Object, ByVal e As EventArgs)
            Try
                Dim btnCalculate As Button = CType(sender, Button)
                Dim gvRow As GridViewRow = CType(btnCalculate.NamingContainer, GridViewRow)
                btnCalculate.CommandArgument = "Calculate"
            Catch ex As Exception
 
            End Try
        End Sub
    End Class
 

[kadghar]

When you clic the button below, the page loads again. if you dont generate the gv again, there is no reason for it to be shown.

[joss Perold]

Thanks for the prompt reply, so as i understand it the grid has to be rebuilt, thats fine, but how do i do that if the onclick event doesnt fire?

[kadghar]

Mmm, perhaps the problem is because the page loads first, and then try to runs an event that isn't handled anymore... I'm not sure, but that could be he problem. Working with code created controls always give trouble in aspx.

Have you tried to create it in your project, and fill it with your info at runtime? just put it into a div that runs at server, with its display set to 'none' and set it to 'block' when you want to see it (or with its visible attribute).

[Rob S]

Have you found an answer to this problem yet?

[Marknut]

I don’t understand what the footer button, “Calculate,” does. Does it calculate the contents of the gridivew? If so, where does the calculation go?

Without the answers to those questions, the closest fix I can come up with is to use JavaScript for the “onClick” event of the button and finish the javascript code with “ return false;” so that there’s no postback.