Load combobox within radgrid

[Wiliam]

I'm trying to load the combobox that is inside the radgrid using the RadGrid1_ItemCommand, using the command to insert a new line into the radgrid that is empty, but the following error is displayed: Can not convert an object of type 'Telerik.Web.UI .GridCommandItem 'in type' Telerik.Web.UI.GridEditableItem. Here's a part of the code:

<telerik:RadGrid ID="RadGrid1" runat="server" ShowStatusBar="true" AllowSorting="true" SortingSettings-EnableSkinSortStyles="false"
                                      AllowAutomaticDeletes="true" AllowAutomaticInserts="true" AllowAutomaticUpdates="True" AllowMultiRowSelection="true"
                                      HorizontalAlign="Center" PageSize="10" EnableViewState="false" >
                         <MasterTableView AutoGenerateColumns="false" CommandItemDisplay="Top" DataKeyNames="NRO_ITEM"  >
                             <NoRecordsTemplate>
                                 <div> Sem itens </div>
                             </NoRecordsTemplate>
                               <Columns>
                                   <telerik:GridBoundColumn UniqueName="TRB_LOTE_NRO" DataField="TRB_LOTE_NRO" HeaderText="TRB_LOTE_NRO"/>
                                   <telerik:GridBoundColumn UniqueName="QUANTIDADE" DataField="QUANTIDADE" DataType="System.Int32" HeaderText="QUANTIDADE"/>
                                   <telerik:GridBoundColumn UniqueName="TIPO" DataField="TIPO" HeaderText="TIPO"/>
                                   <telerik:GridBoundColumn UniqueName="DESCRICAO" DataField="DESCRICAO" HeaderText="DESCRICAO" />
                                   <telerik:GridBoundColumn UniqueName="ID_RT" DataField="ID_RT" HeaderText="RT" />
                                   <telerik:GridBoundColumn UniqueName="ID_NRO_GMM" DataField="ID_NRO_GMM" HeaderText="ID_NRO_GMM"  DataType="System.Int32" Visible="false" />
                                   <telerik:GridBoundColumn UniqueName="NRO_ITEM" DataField="NRO_ITEM" HeaderText="NRO_ITEM" DataType="System.Int32" Visible="false" />
                                   <telerik:GridEditCommandColumn HeaderStyle-Width="100px" HeaderText="Edita" />
                                   <telerik:GridButtonColumn CommandName="Delete" UniqueName="DeleteColumn" HeaderStyle-Width="100px" Text="Delete"/>
                               </Columns>
                       <EditFormSettings EditFormType="Template">
                       <FormTemplate>
                           <div style="width: 300px" >
                               <div style="margin:5px;">
                                   <asp:Label ID="TRB_LOTE_NROLbl" runat="server" Text="Trb_Lote_Nro:" /> <telerik:RadComboBox ID="TRB_LOTE_NROCmbGrid" runat="server" Text='<%# Bind("TRB_LOTE_NRO") %>' />
                               </div>
                               <div style="margin:5px;">
                                   <asp:Label ID="QUANTIDADELbl" runat="server" Text="Quantidade:" meta:resourceKey="QUANTIDADELbl"/> <asp:TextBox ID="QUANTIDADETxtGrid" runat="server" Text='<%# Bind("QUANTIDADE") %>'/>
                               </div>
                               <div style="margin:5px;">
                                   <asp:Label ID="TIPOLbl" runat="server" Text="Tipo:" /> <telerik:RadComboBox ID="TIPOCmbGrid" runat="server" />
                               </div>
                               <div style="margin:5px;">
                                   <asp:Label ID="DESCRICAOLbl" runat="server" Text="Descrição:"/> <asp:TextBox ID="DESCRICAOTxtGrid" runat="server" Text='<%# Bind("DESCRICAO") %>'/>
                               </div>
                               <div style="margin:5px;">
                                   <asp:Label ID="ID_RT" runat="server" Text="RT:"/> <telerik:RadComboBox ID="ID_RTCmbGrid" runat="server" Text='<%# Bind("ID_RT") %>' />
                               </div>
                               <div style="margin:10px;text-align:right;">
                                   <telerik:RadButton ID="btnUpdate" Text='<%# IIf((TypeOf (Container) Is GridEditFormInsertItem), AddJS, UpdateJS) %>' runat="server" CommandName='<%# IIf((TypeOf (Container) Is GridEditFormInsertItem), "PerformInsert", "Update")%>'/>
                                   <telerik:RadButton ID="btnCancel" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancelar" />
                               </div>
                           </div>
                       </FormTemplate>
                   </EditFormSettings>
               </MasterTableView>
               <ClientSettings  EnableRowHoverStyle="true">
                   <Selecting AllowRowSelect="true" />
                   <ClientEvents OnRowDblClick="RowDblClick" />
                    <Scrolling AllowScroll="True" />
               </ClientSettings>
           </telerik:RadGrid>

Private Sub RadGrid1_ItemCommand(sender As Object, e As GridCommandEventArgs) Handles RadGrid1.ItemCommand

       If e.CommandName = RadGrid.InitInsertCommandName Then '"Add new" button clicked
           e.Canceled = True
           Dim newValues As New System.Collections.Specialized.ListDictionary()
           newValues("ID_RT") = ""
           newValues("DESCRICAO") = ""
           newValues("QUANTIDADE") = ""
           newValues("TRB_LOTE_NRO") = ""
           newValues("NRO_ITEM") = ""
           e.Item.OwnerTableView.InsertItemPageIndexAction = GridInsertItemPageIndexAction.ShowItemOnCurrentPage
           e.Item.OwnerTableView.InsertItem(newValues)

           'If Not (TypeOf e.Item Is IGridInsertItem) Then

           Dim editform As GridEditFormItem = DirectCast(DirectCast(e.Item, Telerik.Web.UI.GridDataItem).EditFormItem, GridEditFormItem)
           Dim comboTrbLote As RadComboBox = DirectCast(editform.FindControl("TRB_LOTE_NROCmbGrid"), RadComboBox)
           Dim comboTipo As RadComboBox = DirectCast(editform.FindControl("TIPOCmbGrid"), RadComboBox)
           Dim comboRT As RadComboBox = DirectCast(editform.FindControl("ID_RTCmbGrid"), RadComboBox)

           Expressao = "SELECT DISTINCT ID_EMP_ESTAB FROM EMPRESAS WHERE ESTAB= '" & DepartamentoCmb.Text & "'"


           TabelaAdapter = New OleDbDataAdapter(Expressao, conexao)
           'preenche o datatable
           Tabela = New DataTable
           TabelaAdapter.Fill(Tabela)
           id_estab = Tabela.Rows(0).Item(0).ToString


           Expressao = "SELECT TRABALHOS.ID_NRO_TRAB, TRABALHOS.ID_NRO_MAQ, TRABALHOS.VERSAO FROM TRABALHOS, CONTRATOS " &
                   "WHERE TRABALHOS.ID_CONTRATO = CONTRATOS.ID_CONTRATO AND CONTRATOS.ATIVO=TRUE AND CONTRATOS.ID_EMP_ESTAB = " & id_estab &
                  " ORDER BY TRABALHOS.ID_NRO_TRAB, TRABALHOS.ID_NRO_MAQ, TRABALHOS.VERSAO ASC"

           TabelaAdapter = New OleDbDataAdapter(Expressao, conexao)
           'preenche o datatable
           Tabela = New DataTable
           TabelaAdapter.Fill(Tabela)
           For i = 0 To Tabela.Rows.Count - 1
               comboTrbLote.Items.Add(Tabela.Rows(i).Item(0).ToString & "." & Tabela.Rows(i).Item(1).ToString & "-" & Tabela.Rows(i).Item(2).ToString)
           Next


           Expressao = "SELECT MATERIAL FROM TIPO_MATERIAL_GMM"
           TabelaAdapter = New OleDbDataAdapter(Expressao, conexao)
           Tabela = New DataTable
           TabelaAdapter.Fill(Tabela)
           For i = 0 To Tabela.Rows.Count - 1
               comboTipo.Items.Add(Tabela.Rows(i).Item(0).ToString)
           Next


           Expressao = "SELECT CONTRATOS.ID_CONTRATO, CONTRATOS.ID_EMP_ESTAB, ID_RT " &
                   "FROM EMPRESAS INNER JOIN (CONTRATOS INNER JOIN RTS ON CONTRATOS.ID_CONTRATO = RTS.ID_CONTRATO) " &
                   "ON EMPRESAS.ID_EMP_ESTAB = CONTRATOS.ID_EMP_ESTAB WHERE CONTRATOS.ATIVO=TRUE AND EMPRESAS.ID_EMP_ESTAB = " & id_estab &
                  " ORDER BY ID_RT"


           TabelaAdapter = New OleDbDataAdapter(Expressao, conexao)
           'preenche o datatable
           Tabela = New DataTable
           TabelaAdapter.Fill(Tabela)
           For i = 0 To Tabela.Rows.Count - 1
               comboRT.Items.Add(Tabela.Rows(i).Item(2).ToString)
           Next


       ElseIf (e.CommandName = RadGrid.RebindGridCommandName AndAlso e.Item.OwnerTableView.IsItemInserted) Then
           e.Canceled = True
       Else
           Dim editColumn As GridEditCommandColumn = CType(RadGrid1.MasterTableView.GetColumn("EditCommandColumn"), GridEditCommandColumn)
           If Not editColumn.Visible Then
               editColumn.Visible = True
           End If
       End If
   End Sub

I'll be waiting, thanks
greetings

[Wiliam]

Solved!