[Solved] Dynamically add rows with two radcombo boxes each

[Jay Mehta]

HI,

I am able to add the rows dynamically and preserve the state of it when I just have one radcombo and one textbox, but when I have 2 related radcombobox's (instead of a dropdown and a textbox) for each dynamic row created. On the selection of the first radcombobox's, the second should be populated (for eg. if the person selects state in the first radcombo, the second should populate with the list of states.) 
I tried doing this, I am binding the second drop down box on the selected_indexchange event of the first dropdown, that works fine, but now when I try to add a row , it gives me error on the radgrid.rebind(). Because it is not finding any items in the second radcombobox after the reload.
Any help on this.

<telerik:RadGrid ID="RadGrid1" AutoGenerateColumns="false" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource" >
                <MasterTableView>
                    <Columns>
                        <telerik:GridTemplateColumn UniqueName="TemplateColumn2" HeaderText="Filter Type">
                            <ItemTemplate>
                                <telerik:RadComboBox ID="rcbFilterType" AppendDataBoundItems="true" SelectedValue='<%#Eval("Selected1") %>' runat="server" OnSelectedIndexChanged="rcbFilterType_SelectedIndexChanged" AutoPostBack="true">
                                <Items>
                                <telerik:RadComboBoxItem Value="" Text=""/>
                                <telerik:RadComboBoxItem Value="0" Text="Keyword"/>
                                <telerik:RadComboBoxItem Value="1" Text="State"/>
                                <telerik:RadComboBoxItem Value="2" Text="Provider"/>
                                <telerik:RadComboBoxItem Value="3" Text="Faculty"/>
                                </Items>
                                </telerik:RadComboBox>
                            </ItemTemplate>
                        </telerik:GridTemplateColumn>
                        <telerik:GridTemplateColumn UniqueName="TemplateColumn1" HeaderText="Filter Options">
                            <ItemTemplate>
                                <telerik:RadComboBox ID="rcbFilterOptions" AppendDataBoundItems="true" SelectedValue='<%#DataBinder.Eval(Container.DataItem,"Selected2") %>' runat="server">
                                </telerik:RadComboBox>
                            </ItemTemplate>
                        </telerik:GridTemplateColumn>

                    </Columns>
                </MasterTableView>
        </telerik:RadGrid>

Imports System.Web
Imports System.Web.SessionState
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.HtmlControls
Imports System.Data
Imports Telerik.Web.UI
Imports System.Data.SqlClient

Partial Class Dailog2
    Inherits System.Web.UI.Page
    Public dt As DataTable
    Public _store As String = "FilterTable"

    Protected Sub form2_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Form2.Load
        If Not IsPostBack AndAlso ViewState("dt") = Nothing Then
            If Session(_store) Is Nothing Then
                dt = New DataTable()
                dt.Columns.Add(New DataColumn("Selected1", GetType(String)))
                dt.Columns.Add(New DataColumn("Selected2", GetType(String)))
                'Cache.Remove(_store)
            Else
                dt = DirectCast(Session(_store), DataTable)
            End If
        Else
            ' Cache.Remove(_store)
            dt = DirectCast(ViewState("dt"), DataTable)

        End If

    End Sub

    Private Function AddRow(ByVal dt As DataTable) As DataTable
        ' method to create row
        Dim dr As DataRow = dt.NewRow()
        dr("Selected1") = ""
        dr("Selected2") = ""
        dt.Rows.Add(dr)
        Return dt
    End Function

    Protected Sub Button1_Click1(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim dt As DataTable = DirectCast(ViewState("dt"), DataTable)
        For Each item As GridDataItem In RadGrid1.Items
            Dim ddl1 As RadComboBox = DirectCast(item.FindControl("rcbFilterType"), RadComboBox)
            Dim ddl2 As RadComboBox = DirectCast(item.FindControl("rcbFilterOptions"), RadComboBox)
            Dim i As Integer = 0

            While i < dt.Rows.Count
                If iitem.ItemIndex = i Then
                    dt.Rows(i)(0) = ddl1.SelectedValue
                    dt.Rows(i)(1) = ddl2.SelectedValue
                End If
                System.Math.Max(System.Threading.Interlocked.Increment(i), i - 1)
            End While
        Next

        ViewState("dt") = AddRow(dt)
        RadGrid1.Rebind()
    End Sub

    Protected Sub RadGrid1_NeedDataSource(ByVal source As Object, ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs)
        If Not IsPostBack Then
            ViewState("dt") = dt
            RadGrid1.DataSource = dt
        Else
            dt = DirectCast(ViewState("dt"), DataTable)
            RadGrid1.DataSource = dt
        End If
    End Sub

    Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim dt As DataTable = DirectCast(ViewState("dt"), DataTable)
        For Each item As GridDataItem In RadGrid1.Items
            Dim ddl1 As RadComboBox = DirectCast(item.FindControl("rcbFilterType"), RadComboBox)
            Dim ddl2 As RadComboBox = DirectCast(item.FindControl("rcbFilterOptions"), RadComboBox)
            Dim item1 As New RadComboBoxItem()
            item1.Text = "key1"
            item1.Value = "0"
            Dim i As Integer = 0
            While i < dt.Rows.Count
                If iitem.ItemIndex = i Then
                    dt.Rows(i)(0) = ddl1.SelectedValue
                    dt.Rows(i)(1) = ddl2.SelectedValue

                End If

                System.Math.Max(System.Threading.Interlocked.Increment(i), i - 1)
            End While
        Next
        If (Not ClientScript.IsStartupScriptRegistered("return")) Then
            Page.ClientScript.RegisterStartupScript(Me.GetType(), "return", "returnToParent();", True)
        End If
    End Sub

    Protected Sub rcbFilterType_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim connection As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
        Dim query As String = ""

        Dim ddl1 As RadComboBox = CType(sender, RadComboBox)
        Dim DataItem As GridDataItem = CType(ddl1.NamingContainer, GridDataItem)
        Dim ddl2 As RadComboBox = DirectCast(DataItem.FindControl("rcbFilterOptions"), RadComboBox)

        If ddl1.SelectedValue = 0 Then
            query = "SELECT CategoryID as ID, CategoryName as NAME FROM Categories"
        ElseIf ddl1.SelectedValue = 1 Then
            query = "SELECT CategoryID as ID, CategoryName as NAME FROM Categories"
        ElseIf ddl1.SelectedValue = 2 Then
            query = "SELECT CategoryID as ID, CategoryName as NAME FROM Categories"
        Else
            query = "SELECT CategoryID as ID, CategoryName as NAME FROM Categories"
        End If
        Dim adapter As New SqlDataAdapter(query, connection)
        Dim dt As New DataTable()
        adapter.Fill(dt)

        ddl2.DataTextField = "Name"
        ddl2.DataValueField = "ID"
        ddl2.DataSource = dt
        ddl2.DataBind()
    End Sub


End Class

[Vesko]

You can check the following code-library:

Using related RadComboBoxes in RadGrid

It should give you a hint how to start.

[Jay Mehta]

Hi Sean,

Thank you for that post, but that does not solve my problem, I am able to get the related combo populated, but problem happens, when I added a new row on a button click. It basically preserves the row count in the viewstate and when the page is loaded again, it create the grid with the previous rows and columns with their values. This works fine when I have a radcombo box and a textbox. But problem happens with the related rad combo box's. The first rad combo box has the items so it binds properly on recreation of grid, but the second rad combo box does not have any items bounded to it by default and the value goes out of the range and the error comes.

Any help is appreciated. 

Thank you,

Jay Mehta.