Get the RadComboBox in CommandItemTemplate on Page_Load

[Ali]

Hi,
I am trying to get the RadComboBox [Cmb_Lst_Sel] in CommandItemTemplate on Page_Load. Once I have the list ids [lst_ids] from the RadComboBox [Cmb_Lst_Sel], I pass these IDs to SqlDataSource to filter and rebind the RadGrid [Grd_Url]. But I get error and cannot get a reference to the RadComboBox [Cmb_Lst_Sel]. 

What am I doing wrong?


    ASPX Code:
    ------------------------------------------------------------------------------
    <telerik:RadGrid ID="Grd_Url" runat="server" GridLines="None" AllowSorting="true" AllowPaging="true" PageSize="50"
        AllowFilteringByColumn="true" AutoGenerateColumns="False" AllowMultiRowSelection="true" AllowMultiRowEdit="true"
        AllowAutomaticInserts="True" AllowAutomaticUpdates="True" AllowAutomaticDeletes="True" 
        DataSourceID="Sql_Url" Width="100%">
        <SortingSettings SortToolTip=""/>
        <FilterItemStyle Width="100%"></FilterItemStyle>
        <GroupingSettings CaseSensitive="false"></GroupingSettings>
        <PagerStyle AlwaysVisible="true" Mode="NextPrevAndNumeric"/>
        <MasterTableView DataKeyNames="url_id" CommandItemDisplay="Top" EditMode="InPlace" InsertItemPageIndexAction="ShowItemOnCurrentPage"
            GroupLoadMode="Client" GroupsDefaultExpanded="true" TableLayout="Fixed" Width="100%">
            <GroupByExpressions>
                <telerik:GridGroupByExpression>
                    <SelectFields>
                        <telerik:GridGroupByField FieldName="lst_name"></telerik:GridGroupByField>
                        <telerik:GridGroupByField FieldName="lst_sort"></telerik:GridGroupByField>
                    </SelectFields>
                    <GroupByFields>
                        <telerik:GridGroupByField FieldName="lst_sort" SortOrder="Ascending"></telerik:GridGroupByField>
                        <telerik:GridGroupByField FieldName="lst_name" SortOrder="Ascending"></telerik:GridGroupByField>
                    </GroupByFields>
                </telerik:GridGroupByExpression>
            </GroupByExpressions>
            <CommandItemTemplate>
            <div id="Div_Tlb_Fixed">
                <telerik:RadToolBar ID="Tlb_Url" runat="server" EnableImageSprites="true"
                    OnButtonClick="CsTlbClick" OnClientButtonClicking="jsTlbUrl">
                    <Items>
                        <telerik:RadToolBarButton CommandName="Toggle" PostBack="false" ToolTip="Expand/Collapse Folders"
                            CssClass="Btn_ToggleN" HoveredCssClass="Btn_ToggleH"
                            CheckOnClick="true" AllowSelfUnCheck="true" Group="T">
                        </telerik:RadToolBarButton>
    
                        <telerik:RadToolBarButton CommandName="Clear" PostBack="false" ToolTip="Clear Website Selection"
                            CssClass="Btn_ClearN" HoveredCssClass="Btn_ClearH">
                        </telerik:RadToolBarButton>
                    </Items>
                </telerik:RadToolBar>
                <telerik:RadComboBox ID="Cmb_Lst_Sel" runat="server" DataTextField="lst_name" CheckBoxes="true"
                    DataValueField="lst_id" AutoPostBack="True" EnableCheckAllItemsCheckBox="true" 
                    DataSourceID="Sql_Lst" Width="20%">
                    <Items>
                        <telerik:RadComboBoxItem Text="All" Value="" Selected="true"></telerik:RadComboBoxItem>
                    </Items>
                </telerik:RadComboBox> 
            </div>
            </CommandItemTemplate>
            <Columns>
                <%--Some Columns here--%>
            </Columns>
        </MasterTableView>
    </telerik:RadGrid>
    
    <asp:SqlDataSource ID="Sql_Lst" runat="server" OnSelecting="CsSqlSelectingCmb"
    ConnectionString="<%$ ConnectionStrings:Con_Str %>"
        SelectCommand="SELECT [lst_id], [lst_name] 
                       FROM [t_Lists] 
                       WHERE [usr_id] = @usr_id 
                       ORDER BY [lst_sort]">
        <SelectParameters>
            <asp:Parameter Name="usr_id"/>
        </SelectParameters>
    </asp:SqlDataSource>
    
    
    C# Code:
    ------------------------------------------------------------------------------
    
        public partial class Cls_Url : System.Web.UI.UserControl
        {
            protected void Page_Load(object s, EventArgs e)
            {
                // Grab the RadComboBox in CommandItemTemplate on Page_Load
                CsSqlSelect(s, e);
            }
    
            protected void CsSqlSelect(object s, EventArgs e)
            {
                // I get error for the 2 lines below and cannot get a reference to the RadComboBox [Cmb_Lst_Sel]
                // What am I doing wrong?
                GridItem cmdItem = Grd_Url.MasterTableView.GetItems(GridItemType.CommandItem)[0];
                RadComboBox cmbLst = (RadComboBox)cmdItem.FindControl("Cmb_Lst_Sel");
    
                if (cmbLst.CheckedItems.Count > 0)
                {
                    var items = cmbLst.CheckedItems;
                    string lst_ids = "";
    
                    foreach (var item in items)
                    {
                        lst_ids += "'" + item.Value + "'" + ",";
                    }
    
                    lst_ids = lst_ids.Remove(lst_ids.Length - 1);
                }
    
                // Once I have the list ids [lst_ids] from the RadComboBox [Cmb_Lst_Sel], 
                // I pass these IDs to SqlDataSource to filter and rebind the RadGrid [Grd_Url]
            }
    
            protected void CsTlbClick(object s, RadToolBarEventArgs e)
            {
            }
    
            protected void CsSqlSelectingCmb(object s, SqlDataSourceCommandEventArgs e)
            {
                e.Command.Parameters["@usr_id"].Value = Membership.GetUser(HttpContext.Current.User.Identity.Name).ProviderUserKey;
            }
    
        } 

    ------------------------------------------------------------------------------

[Radoslav]

Hello,

To achieve the desired functionality you need to execute the code on RadGrid’s PreRender event instead of on PageLoad and to call RadGrid’s Rebind() method. I am sending you a simple example based on your code which demonstrates the desired functionality.

I hope this helps.  

Regards,
Radoslav
Telerik