[Solved] Adding columns in page_init but getting Multiple Controls With The Same ID

[Nick]

Hi,


I'm using RadControls for ASP.NET AJAX Q1 2009


I have a radgrid using NeedDataSource to bind to a dynamicallyt created datasource, depending on columns the user has selected. The grid is created in page_init as recommended to me.

I dynamically create the grid columns myself. One fo these columns is a template column containing a radeditor. I was advised to create columns, especially templated columns, in page_init. When I do this though, I get

Multiple controls with the same ID 'FilterTextBox_tblT1Devices.Name' were found. FindControl requires that controls have unique IDs.

If I create the columns in page load I don't get this message but my template column will disappear after postback as expected, because it's viewstate is not saved.

Another issue is my dynamically created dropdown columns are completely blank no matter what way I configure them. I have had problems with them for days. I'm hoping their problem might be related.

Please advise.


Relevant code :

    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init


        ' If loading for the first time...

        'Create the Grid
        Dim grid As New RadGrid()
        grid.ID = "gridServers"
        grid.Skin = "Default"
        grid.PageSize = 100
        grid.AllowPaging = True
        grid.AllowFilteringByColumn = True
        grid.AllowSorting = True
        grid.ShowGroupPanel = True
        grid.PagerStyle.Mode = GridPagerMode.NextPrevAndNumeric
        grid.AutoGenerateColumns = False
        grid.CssClass = "gridServers"

        AddHandler grid.ColumnCreated, AddressOf gridServers_ColumnCreated
        AddHandler grid.NeedDataSource, AddressOf gridServers_NeedDataSource

        gridServersHere.Controls.Add(grid)


        ' Initialize the page
        Initialize()
        rptColumnSelector.DataSource = Session("showColumns")
        rptColumnSelector.DataBind()
        PrepareGridColumns()

    End Sub


    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        ' If loading for the first time...
        If Not Page.IsPostBack Then

            ' Initialize the page
            'Initialize()
            'PrepareGridColumns()
            rptColumnSelector.DataSource = Session("showColumns")
            rptColumnSelector.DataBind()
            'gridServers.DataBind()
        End If
    End Sub


    Protected Function getDataString() As String

        Dim columnList As Data.DataTable = Session("showColumns")
        Dim selectStr As String = ""
        Dim joinstr As String = ""
        Dim column As Data.DataRow
        Dim i = 0

        selectStr = "select tblT1Devices.DeviceID as [Device ID], tblT2Configuration.EnvironmentID as [ThisID] "

        'build a comma-delimited list of columns that will make up the SQL Query.
        'Dont put a comma after the last one.
        If columnList Is Nothing Then
            Initialize()
            columnList = Session("showColumns")
        End If

        For Each column In columnList.Rows
            ' Process only the checked columns.
            If column("Checked") = True Then

                selectStr = selectStr + ", " + column("FullName") + " as [" + column("FullName") + "]"


                ' Commented out at the moment. We are doing the simple version above.



                '                Select Case column("LookupTable")

                ' If this is a straight forward field :
                '                   Case ""
                '              selectStr = selectStr + ", " + column("FullName") + " as [" + column("FullName") + "]"


                'Otherwise is must be a lookup ID :
                '                 Case Else
                '            selectStr = selectStr + ", "
                '           selectStr = selectStr + column("TABLE_NAME") + column("COLUMN_NAME") + "." + column("LookupValue") + " as [" + column("FullName") + "]"

                'Join Str is a string we're contructing of SQL Joins, while we'rein the same loop. This will be tagged on the end of
                'selectstr after this loop.

                '          joinstr = joinstr + " left join " + column("LookupTable") + " as " + column("TABLE_NAME") + column("COLUMN_NAME")
                '         joinstr = joinstr + " on " + column("TABLE_NAME") + column("COLUMN_NAME") + "." + column("LookupID") + " = " + column("FullName")
                '        End Select


            End If
            'If i < columnCount Then selectStr = selectStr + ","
            'i += 1
        Next

        selectStr = selectStr + " from tblT1Devices left join tblt2configuration on tblT2configuration.deviceID = tblT1Devices.deviceid"
        selectStr = selectStr + " left join tblt3_MV_Configuration on tblT3_MV_Configuration.deviceID = tblT1Devices.deviceid"
        'selectStr = selectStr + joinstr

        Return selectStr

    End Function


    Protected Sub Initialize()

        Dim column As DataRow

        Dim ColumnList As Data.DataTable = CreateColumnListDataTable()

        'A list of Column Names we want to show by default on the Grid:
        Dim SelectedColumns As String() = {"tblT1Devices.Name", "tblT1Devices.Domain"}
        Dim selectColumn As String

        'Get all available columns from the SP
        Dim ConnString As String = ConfigurationManager.ConnectionStrings("WPG_ADBConnectionString").ConnectionString
        Dim conn As SqlConnection = New SqlConnection(ConnString)
        Dim adapter As SqlDataAdapter = New SqlDataAdapter
        adapter.SelectCommand = New SqlCommand("exec sp_web_Search_GetAvailableColumns", conn)

        Dim table1 As New DataTable
        conn.Open()
        Try
            adapter.Fill(table1)
        Finally
            conn.Close()
        End Try


        'We add a column here that will hold whether the column is checked on the GUI
        'Then Cycle through all the checkboxes and check those that match the default list above
        Dim myDataColumn As DataColumn

        myDataColumn = New DataColumn()
        myDataColumn.DataType = Type.GetType("System.Boolean")
        myDataColumn.ColumnName = "Checked"
        table1.Columns.Add(myDataColumn)

        For Each column In table1.Rows
            column("Checked") = False ' Check them all to false by default.
            For Each selectColumn In SelectedColumns
                If selectColumn = column("FullName") Then
                    column("Checked") = True 'check them to true if in the list above.
                End If
            Next
        Next

        'Set the FullName Column as the PrimaryKey
        'Dim Key() As DataColumn
        'Key(0) = table1.Columns("FullName")
        'Key(0) = table1.Columns.Item("FullName")
        'table1.PrimaryKey = Key


        'For Each item In rpt.Items
        '        chk = item.FindControl("chkColumn")
        'chkColumn = chk.ToolTip.Split("-")
        'For Each selectColumn In SelectedColumns
        '        If selectColumn = chkColumn(0) Then
        '        chk.Checked = "true"
        'End If
        'Next
        'Next

        'update the session variable of checked columns
        Session("showColumns") = table1

    End Sub

    Protected Sub gridServers_ColumnCreated(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridColumnCreatedEventArgs)

        Dim ColumnList As DataTable = Session("showColumns")
        Dim myColumn As DataRow


        'Go through all columns and perform specific tasks depending on row types.
        For Each myColumn In ColumnList.Rows

            'For any columns in the grid that match our datatable of extra column data ... :
            'If e.Column.UniqueName = myColumn("FullName") Then
            '            e.Column.HeaderText = myColumn("FriendlyColumnName")
            'e.Column.HeaderTooltip = e.Column.HeaderTooltip + " - " + myColumn("FullName") & " - " & myColumn("Description")

            'Detect column types and set to readonly if the column is readonly.
            'Select Case e.Column.ColumnType

            '    Case "GridBoundColumn"
            'Dim boundColumn As GridBoundColumn = CType(e.Column, GridColumn)
            'boundColumn.ReadOnly = Boolean.Parse(myColumn("Readonly"))
            'If Not boundColumn.ReadOnly Then e.Column.HeaderStyle.ForeColor = System.Drawing.ColorTranslator.FromHtml("#0269ff")

            'Case "GridCheckBoxColumn"
            'Dim boundColumn As GridCheckBoxColumn = CType(e.Column, GridColumn)
            'boundColumn.ReadOnly = Boolean.Parse(myColumn("Readonly"))
            'If Not boundColumn.ReadOnly Then e.Column.HeaderStyle.ForeColor = System.Drawing.ColorTranslator.FromHtml("#0269ff")

            'End Select


            'Check for Lookup tables and change the column type to dropdowns for editing purposes
            ' Note that the grid doesnt autodetect this osrt of thing (like checkboxes) so we have to tell it to.
            ' Otherwise it will just use GridBoundColumn

            'If a lookup table is specified
            'If myColumn("Lookuptable") <> "" Then
            ' e.Column.co()
            'End If


            'End If


            'If the column is the DeviceID, make sure this is readonly as it is the primary key.
            If e.Column.UniqueName = "Device ID" Then
                Dim boundColumn As GridBoundColumn = CType(e.Column, GridBoundColumn)
                boundColumn.ReadOnly = True
            End If
        Next



        ' For edit column
        If e.Column.ColumnType = "Telerik.Web.UI.GridEditCommandColumn" Then

        End If




    End Sub


    Protected Sub gridServers_UpdateCommand(ByVal source As Object, ByVal e As Telerik.Web.UI.GridCommandEventArgs)

        Dim ColumnList As Data.DataTable = Session("showColumns")
        Dim columnName As Data.DataRow


        Dim sqlstring = ""
        Dim w = "Telerik.Web.UI.GridEditFormItem"

        'Get the GridEditableItem of the RadGrid
        Dim editedItem As GridEditableItem = TryCast(e.Item, GridEditableItem)

        'Get the primary key value using the DataKeyValue.
        Dim DeviceID As String = editedItem.OwnerTableView.DataKeyValues(editedItem.ItemIndex)("Device ID").ToString()

        Dim sql As SqlDataSource = New SqlDataSource
        sql.ConnectionString = ConfigurationManager.ConnectionStrings("WPG_ADBConnectionString").ConnectionString

        'have to put at least one update statement (deviceid = deviceid) so anything added after has a comma before it
        sqlstring = "Update tblT3_MV_Configuration set DeviceID = " & DeviceID & " "


        For Each columnName In ColumnList.Rows

            'only if column is readonly and checked.....
            If columnName("ReadOnly") <> "true" And columnName("Checked") Then

                Dim name As String = editedItem(columnName(5)).controls(0).GetType().ToString()

                Select Case editedItem(columnName("Fullname")).controls(0).GetType().ToString()

                    Case "System.Web.UI.WebControls.TextBox"
                        sqlstring = sqlstring & ", " & columnName(0) & " = '" & (TryCast(editedItem(columnName("Fullname")).Controls(0), TextBox)).Text & "', "

                    Case "System.Web.UI.WebControls.CheckBox"
                        sqlstring = sqlstring & ", " & columnName("FullName") & " = '" & (TryCast(editedItem(columnName("Fullname")).Controls(0), CheckBox)).Checked.ToString & "', "

                    Case "System.Web.UI.WebControls.dropdownlist"
                        sqlstring = sqlstring & ", " & columnName("FullName") & " = '" & (TryCast(editedItem(columnName("Fullname")).Controls(0), DropDownList)).SelectedItem.Value & "', "

                        'might use this later :
                        'telerik.Web.UI.RadDateInput

                End Select
            End If
        Next

        sqlstring = sqlstring & " where DeviceID = " & DeviceID

        'Will do update here......
    End Sub


    Protected Sub gridServers_NeedDataSource(ByVal source As Object, ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs)

        'Set up grid columns acording to our selected column list
        'Not any more, do this in Page_init
        'PrepareGridColumns()

        Dim gridServers As RadGrid = source
        Dim value() As String = {"Device ID"}
        gridServers.DataSource = GetDataTable()
        gridServers.MasterTableView.DataKeyNames = value

    End Sub


    Public Function GetDataTable() As DataTable
        Dim ConnString As String = ConfigurationManager.ConnectionStrings("WPG_ADBConnectionString").ConnectionString
        Dim conn As SqlConnection = New SqlConnection(ConnString)
        Dim adapter As SqlDataAdapter = New SqlDataAdapter
        adapter.SelectCommand = New SqlCommand(getDataString(), conn)
        Dim table1 As New DataTable
        conn.Open()
        Try
            adapter.Fill(table1)
        Finally
            conn.Close()
        End Try
        Return table1
    End Function



    Public Sub PrepareGridColumns()


        'This function will generate the columns for the Grid by looping through the checkbox datatable
        ' Instead of autogenerating, this way I can handpick and identify the dropdown\lookup columns

        Dim gridServers As RadGrid = gridServersHere.FindControl("gridServers")
        Dim column As DataRow
        Dim columnList As DataTable = Session("showColumns")
        Dim AnyColumnsAreEditable As Boolean = False

        'Clear Columns
        gridServers.Columns.Clear()

        Dim editcol As New GridEditCommandColumn()
        gridServers.MasterTableView.Columns.Add(editcol)


        Dim sql1 As New SqlDataSource
        sql1.ID = "sqlEnv"
        sql1.ConnectionString = ConfigurationManager.ConnectionStrings("WPG_ADBConnectionString").ConnectionString
        sql1.SelectCommand = "select * from tblT3Environments"

        Dim dd As New GridDropDownColumn

        gridServers.MasterTableView.Columns.Add(dd)
        dd.ListValueField = "EnvironmentID"
        dd.ListTextField = "Environment"
        dd.DataSourceID = sql1.ID
        dd.HeaderText = "Scooby"
        dd.DataField = "ThisID"

        For Each column In columnList.Rows
            If column("Checked") Then

                If column("LookupTable") <> "" Then

                    Dim sql As New SqlDataSource
                    sql.ID = "sql" & column("Table_Name") & column("column_Name")
                    sql.ConnectionString = ConfigurationManager.ConnectionStrings("WPG_ADBConnectionString").ConnectionString
                    sql.SelectCommand = "select " & column("LookupID") & ", " & column("LookupValue") & " from " & column("LookupTable")

                    Dim dropdowncol As New GridDropDownColumn

                    gridServers.MasterTableView.Columns.Add(dropdowncol)
                    dropdowncol.ListValueField = column("LookupID")
                    dropdowncol.ListTextField = column("LookupValue")
                    dropdowncol.DataSourceID = sql.ID
                    dropdowncol.HeaderText = column("FriendlyColumnName")
                    dropdowncol.DataField = column("FullName")
                    dropdowncol.UniqueName = column("FullName")
                    dropdowncol.ReadOnly = Boolean.Parse(column("Readonly"))
                    dropdowncol.SortExpression = column("FullName")
                    dropdowncol.Groupable = True
                    dropdowncol.GroupByExpression = column("FullName") + " Group By " + column("FullName")

                Else

                    If column("DATA_TYPE") = "varchar" Or column("DATA_TYPE") = "nvarchar" Then

                        Dim boundcol As New GridBoundColumn()
                        gridServers.MasterTableView.Columns.Add(boundcol)
                        boundcol.UniqueName = column("FullName")
                        boundcol.HeaderText = column("FriendlyColumnName")
                        boundcol.DataField = column("FullName")
                        boundcol.HeaderTooltip = boundcol.HeaderTooltip.ToString() + " - " + column("FullName") & " - " & column("Description")
                        boundcol.ReadOnly = Boolean.Parse(column("Readonly"))
                        boundcol.SortExpression = column("FullName")
                        boundcol.Groupable = True
                        boundcol.GroupByExpression = column("FullName") + " Group By " + column("FullName")




                    ElseIf column("DATA_TYPE") = "datetime" Then

                        Dim datecol As New GridDateTimeColumn()
                        gridServers.MasterTableView.Columns.Add(datecol)
                        datecol.UniqueName = column("FullName")
                        datecol.HeaderText = column("FriendlyColumnName")
                        datecol.DataField = column("FullName")
                        datecol.HeaderTooltip = datecol.HeaderTooltip.ToString() + " - " + column("FullName") & " - " & column("Description")
                        datecol.ReadOnly = Boolean.Parse(column("Readonly"))
                        datecol.PickerType = GridDateTimeColumnPickerType.DateTimePicker


                    ElseIf column("DATA_TYPE") = "int" Or column("DATA_TYPE") = "bigint" Then

                        Dim intcol As New GridNumericColumn()
                        gridServers.MasterTableView.Columns.Add(intcol)
                        intcol.UniqueName = column("FullName")
                        intcol.HeaderText = column("FriendlyColumnName")
                        intcol.DataField = column("FullName")
                        intcol.HeaderTooltip = intcol.HeaderTooltip.ToString() + " - " + column("FullName") & " - " & column("Description")
                        intcol.ReadOnly = Boolean.Parse(column("Readonly"))


                    ElseIf column("DATA_TYPE") = "text" Then

                        Dim tempcol As New GridTemplateColumn()

                        'The class for this template can be found at the bottom of this code-behind
                        tempcol.EditItemTemplate = New MyEditBoxTemplate(column("FullName"))

                        tempcol.UniqueName = column("FullName")
                        tempcol.HeaderText = column("FriendlyColumnName")
                        tempcol.DataField = column("FullName")
                        tempcol.HeaderTooltip = tempcol.HeaderTooltip.ToString() + " - " + column("FullName") & " - " & column("Description")
                        tempcol.ReadOnly = Boolean.Parse(column("Readonly"))
                        gridServers.MasterTableView.Columns.Add(tempcol)

                    ElseIf column("DATA_TYPE") = "bit" Then

                        Dim Checkcol As New GridCheckBoxColumn()
                        gridServers.MasterTableView.Columns.Add(Checkcol)
                        Checkcol.UniqueName = column("FullName")
                        Checkcol.HeaderText = column("FriendlyColumnName")
                        Checkcol.DataField = column("FullName")
                        Checkcol.HeaderTooltip = Checkcol.HeaderTooltip.ToString() + " - " + column("FullName") & " - " & column("Description")

                        Checkcol.ReadOnly = Boolean.Parse(column("Readonly"))

                    Else
                        Dim boundcol As New GridBoundColumn()
                        gridServers.MasterTableView.Columns.Add(boundcol)
                        boundcol.UniqueName = column("FullName")
                        boundcol.HeaderText = column("FriendlyColumnName")
                        boundcol.DataField = column("FullName")
                        boundcol.HeaderStyle.ForeColor = Drawing.Color.Red
                        boundcol.HeaderTooltip = boundcol.HeaderTooltip.ToString() + " - " + column("FullName") & " - " & column("Description")
                        boundcol.ReadOnly = Boolean.Parse(column("Readonly"))

                    End If

                End If

            End If
        Next


    End Sub
    Private Class MyEditBoxTemplate
        Implements ITemplate

        Protected EditBox As RadEditor

        Private colname As String

        Public Sub New(ByVal cName As String)
            MyBase.New()
            colname = cName
        End Sub

        Public Sub InstantiateIn(ByVal container As System.Web.UI.Control) Implements ITemplate.InstantiateIn

            EditBox = New RadEditor
            EditBox.ID = "editBox"

            'Format edit Box
            EditBox.Width = "500"
            EditBox.Width = "300"

            Dim myTools() As String = {"ToggleScreenMode", "Bold", "Italic", "Underline", "Fontsize", "Fontname", "Cut", "Copy", "Paste", _
                                       "Undo", "Redo", "Indent", "Outdent"}
            Dim toolname As String
            Dim Main As New EditorToolGroup()
            For Each toolname In myTools
                Dim tool As New EditorTool(toolname)
                tool.Type = EditorToolType.Button
                Main.Tools.Add(tool)
            Next

            EditBox.Tools.Add(Main)

            AddHandler EditBox.DataBinding, AddressOf Me.EditBox_DataBinding
            container.Controls.Add(EditBox)
        End Sub

        Private Sub EditBox_DataBinding(ByVal sender As Object, ByVal e As EventArgs)
            Dim eBox As RadEditor = CType(sender, RadEditor)
            Dim container As GridEditFormItem = CType(eBox.NamingContainer, GridEditFormItem)
            'eBox.Content = CType(container.DataItem, DataRowView)(colname).ToString()
            eBox.Content = "<b>Server Notes</b><br/><br/>Previous server notage may not be modified. Any notes written and saved here will be appended."
        End Sub

    End Class

End Class

[Tsvetoslav]

Hello Nick,

From the code snippets it is difficult to say what exactly might be throwing this exception. However, I'd like to draw you attention to a couple of points:

1. Please, review the following help article on the programmatic creation of the gird in Page_Init : http://www.telerik.com/help/aspnet-ajax/grdprogrammaticcreation.html
and the following couple of online examples on Simple Data Binding (http://demos.telerik.com/aspnet-ajax/grid/examples/programming/simplebinding/defaultcs.aspx) and Advanced Data Binding (http://demos.telerik.com/aspnet-ajax/grid/examples/programming/needdatasource/defaultcs.aspx)

2. You should not be binding the grid neither in the Page_Init event nor in the Page_Load event. The NeedDataSource handler is completely sufficient for the grid to bind properly.

Please, give this suggestions a try and see if they help.

Kind regards,
Tsvetoslav
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Check out the tips for optimizing your support resource searches.