[Solved] Creating GridTemplateColumn in code behind

[RJ]

Hi how can I create gridtemplatecolumn in code behind. currently I'm creating my grid purely on codebehind. There where no problem using bound column and dropdown column but I need to create a template column which at the moment I dont know how to instantiate like asp checkbox or a label. Any information would be much appreciated.

Thank in advance,
RJ

[Shinu]

Hello,

Checkout the part "Creating template columns programmatically" in the following documentation which describes how to add GridTemplateColumn dynamically.
Programmatic creation

Hope this helps,
Shinu.

[RJ]

Hi Shinu, I was able to create my template checkbox but using the template checkbox generated using code behind gives me error when I use it to delete items that are checked.

Heres my old code using aspx columns:

<rad:GridTemplateColumn HeaderText="Delete" Groupable="False" UniqueName="TemplateColumn" HeaderImageUrl="images/delete.gif">
                                    <ItemStyle HorizontalAlign="Center" Width="35px" CssClass="ResizeItem" VerticalAlign="Middle"></ItemStyle>
                                    <HeaderStyle Font-Size="XX-Small" Font-Underline="True" Font-Names="Arial" HorizontalAlign="Center"
                                        ForeColor="Blue" Width="23px" VerticalAlign="Middle"></HeaderStyle>
                                    <ItemTemplate>
                                        <asp:CheckBox id="CheckBox1" runat="server" AutoPostBack="false" OnCheckedChanged="CheckChanged"></asp:CheckBox>
                                    </ItemTemplate>
                                </rad:GridTemplateColumn>








Private ReadOnly Property CustomersChecked() As Hashtable
        Get
            Dim res As Object = ViewState("_cc")
            If res Is Nothing Then
                res = New Hashtable
                ViewState("_cc") = res
            End If

            Return CType(res, Hashtable)
        End Get
    End Property

    Protected Sub CheckChanged(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim box As CheckBox = CType(sender, CheckBox)
        Dim item As GridDataItem = CType(box.NamingContainer, GridDataItem)
        Dim target As Hashtable = Nothing

        target = CustomersChecked

        If box.Checked Then
            DeletedItems &= item.GetDataKeyValue("ID").ToString & ","
            target(item.GetDataKeyValue("ID").ToString) = True
        Else
            DeletedItems = ""
            target(item.GetDataKeyValue("ID").ToString) = Nothing
        End If
    End Sub

Private Sub RadGrid_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.WebControls.GridItemEventArgs) Handles CensusGrid.ItemDataBound
Try
            If TypeOf e.Item Is GridDataItem Then
                Dim item As GridDataItem = e.Item

                Dim box As CheckBox = CType(item.FindControl("CheckBox1"), CheckBox)
                Dim isChecked As Object = Nothing


                isChecked = CustomersChecked(item("ID").Text)


                box.Checked = False
            End If
        Catch ex As Exception

        End Try
End Sub

I replaced my static column and replaced it with this one

Try
                Dim templateColumnName As String = "Delete"
                Dim templateColumn As New GridTemplateColumn()
                templateColumn.ItemTemplate = New GridCheckboxTemplate(templateColumnName)
                templateColumn.HeaderImageUrl = "images/delete.gif"
                templateColumn.ItemStyle.HorizontalAlign = HorizontalAlign.Center
                templateColumn.HeaderStyle.HorizontalAlign = HorizontalAlign.Left
                templateColumn.ItemStyle.VerticalAlign = VerticalAlign.Middle
                templateColumn.HeaderStyle.Width = Unit.Pixel(23)
                templateColumn.ItemStyle.Width = Unit.Pixel(35)
                RadGrid.MasterTableView.Columns.Add(templateColumn)
            Catch ex As Exception

            End Try


Private Class GridCheckboxTemplate
        Implements ITemplate
        Protected boolValue As CheckBox
        Private colname As String
        Public Sub New(ByVal cName As String)
            colname = cName
        End Sub
        Public Sub InstantiateIn(ByVal container As System.Web.UI.Control) Implements ITemplate.InstantiateIn

            boolValue = New CheckBox()
            boolValue.ID = "CheckBox1"
            AddHandler boolValue.DataBinding, _
                       AddressOf boolValue_DataBinding
            boolValue.Enabled = True
            container.Controls.Add(boolValue)
        End Sub
        Sub boolValue_DataBinding(ByVal sender As Object, ByVal e As EventArgs)
            Dim cBox As CheckBox = DirectCast(sender, CheckBox)
            Dim container As GridDataItem = DirectCast(cBox.NamingContainer, GridDataItem)

        End Sub

    End Class

 and created addhandler on itemcreated

 Private Sub RadGrid_ItemCreated(ByVal sender As Object, ByVal e As Telerik.WebControls.GridItemEventArgs) Handles CensusGrid.ItemCreated
        If (TypeOf e.Item Is GridDataItem) Then
            Dim ck As CheckBox = CType(e.Item.FindControl("CheckBox1"), CheckBox)
            AddHandler ck.CheckedChanged, AddressOf CheckChanged


        End If
End Sub

but page blows after clicking on delete

Server Error in '/Sample' Application.
--------------------------------------------------------------------------------

Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

What did I miss? or maybe where can I place the CheckChanged?
I already tried it also on ItemDatabound but to no avail.

Thanks again,
RJ

[RJ]

I was able to make page not to blow by creating all columns in code behind but then again new problem came up. My checkbox gridtemplatecolumn disappears when I click on delete. Just created a new thread for this one. Thanks Shinu.