[Solved] Loading user control with Telerik RadGrid at runtime

[Andrew]

Hello!

There is the same article at your documentation.
Quote:
"
Otherwise, you have to load the user control only the first time:
protected void Page_Load(object sender, EventArgs e)
{
        if (Page.FindControl("myUC") == null)
        {
            Control myControl = this.LoadControl("gridUC.ascx");
            myControl.ID = "myUC";
            this.Panel1.Controls.Add(myControl);
        }
}
"

I want to know if we add controls dynamically we should restore it at every postback. So if (Page.FindControl("myUC") == null) will always true, and control would be recreated.

Dynamically creation userControl at Page_Init is not possible for me. Could u give some comment?

Thanks, Andrew

[Tsvetina]

Hello Andrew,

In case you load the user control on the first Page_Load, in the default case it should not be null during the next one, as the control will be persisted upon postback. Do you encounter different behavior in your application?

All the best,
Tsvetina
the Telerik team

[Lucania]

I have a RadGrid on a user control that is loaded at runtime. In my case, the control is created in the page's PreInit function.

The RadGrid has an edit template with an Add/Update button on it. I'm finding when I click that button, the PerformInsert/Update Command event is not firing. On investigation, the button is never created on the Update postback, but I'm not sure it needs to be if the event that's being generated is actually an ItemCommand event for the grid. Is there any way to handle this scenario?

Thanks

Ross Crawford

[Lucania]

Some additional info, I've included relevant front end code from the control below. Also, when I click the update button the Page_Load event fires for the control, and the __EVENTTARGET confirms that it was initiated by the update button. But the ItemCommand for the grid is never called.

Front-end:

<telerik:RadAjaxManagerProxy runat="server" ID="rapExpenses" >
    <AjaxSettings>
        <telerik:AjaxSetting AjaxControlID="pnlExpenses">
            <UpdatedControls>
                <telerik:AjaxUpdatedControl ControlID="pnlExpenses" />
            </UpdatedControls>
        </telerik:AjaxSetting>
        <telerik:AjaxSetting AjaxControlID="rgClientExpenseCategory">
            <UpdatedControls>
                <telerik:AjaxUpdatedControl ControlID="rgClientExpenseCategory" />
            </UpdatedControls>
        </telerik:AjaxSetting>
    </AjaxSettings>
</telerik:RadAjaxManagerProxy>

<asp:Panel ID="pnlExpenses" runat="server">

    <asp:HiddenField ID="EditorUser" runat="server" />
    <asp:HiddenField ID="SelectedClient" runat="server" />
    <asp:HiddenField ID="SelectedPartner" runat="server" />
    <asp:HiddenField ID="SelectedCategory" runat="server" EnableViewState="false" />

    <div id="divClientExpenses" runat="server">
        <p>
            <telerik:RadGrid ID="rgClientExpenseCategory" runat="server" AutoGenerateColumns="false" DataSourceID="dsClientExpenseCategory"
                AllowAutomaticInserts="true" AllowAutomaticUpdates="true" AllowAutomaticDeletes="true" AllowPaging="false"
                OnItemCommand="rgClientExpenseCategory_ItemCommand" OnItemDataBound="rgClientExpenseCategory_ItemDataBound" OnPreRender="rgClientExpenseCategory_PreRender"
                OnItemUpdated="rgClientExpenseCategory_ItemUpdated">
                <ClientSettings EnableRowHoverStyle="true">
                    <ClientEvents OnRowDblClick="RowDblClick" />
                </ClientSettings>
                <MasterTableView Name="rgExpensesCategories_Master" DataSourceID="dsClientExpenseCategory" CommandItemDisplay="Top" AutoGenerateColumns="false" DataKeyNames="CategoryID" TableLayout="Auto" ShowFooter="true" >
                    <NoRecordsTemplate>
                        <center><font color="red"><b>Alert:</b> You have not entered any expense categories for your client.</font></center>
                    </NoRecordsTemplate>
                    <CommandItemStyle CssClass="printerhide" />
                    <CommandItemSettings AddNewRecordText="Add new expense category for your client" />
                    <Columns>
                        <telerik:GridBoundColumn UniqueName="CategoryID" DataField="CategoryID" Visible="false" />
                        <telerik:GridBoundColumn UniqueName="CategoryShortName" HeaderText="Short Name" DataField="CategoryShortName" SortExpression="CategoryShortName" FooterText="Total:" />
                        <telerik:GridBoundColumn UniqueName="CategoryName" HeaderText="Name" DataField="CategoryName" SortExpression="CategoryName" />
                        <telerik:GridNumericColumn UniqueName="AnnualAmount" DataField="AnnualAmount" SortExpression="AnnualAmount" DataFormatString="{0:C2}" HeaderText="Annual Amount" HeaderStyle-HorizontalAlign="Right" ItemStyle-HorizontalAlign="Right" FooterStyle-HorizontalAlign="Right" Aggregate="Sum" />
                        <telerik:GridButtonColumn ItemStyle-CssClass="printerhide" ButtonType="ImageButton" ImageUrl="<%$ AppSettings:GridEditButtonURL %>" UniqueName="EditColumn" CommandName="Edit" Text="Edit" HeaderStyle-Width="12px" />
                        <telerik:GridButtonColumn ItemStyle-CssClass="printerhide" ButtonType="ImageButton" ImageUrl="<%$ AppSettings:GridDeleteButtonURL %>" UniqueName="DeleteColumn" ConfirmText="Really delete?" CommandName="Delete" Text="Delete" HeaderStyle-Width="12px" />
                    </Columns>
                    <DetailTables>
                        <telerik:GridTableView Name="gtvExpenses" DataKeyNames="ExpenseID" CssClass="prplinktable" CommandItemDisplay="Top" DataSourceID="dsClientExpenses">
                            <ParentTableRelation>
                                <telerik:GridRelationFields MasterKeyField="CategoryID" DetailKeyField="CategoryID" />
                            </ParentTableRelation>
                            <NoRecordsTemplate>
                                <center><font color="red"><b>Alert:</b> You have not entered any expenses for your client.</font></center>
                            </NoRecordsTemplate>
                            <CommandItemStyle CssClass="printerhide" />
                            <CommandItemSettings AddNewRecordText="Add new expense for your client" ShowRefreshButton="true"/>
                            <Columns>
                                <telerik:GridBoundColumn UniqueName="Description" DataField="Description" SortExpression="Description" HeaderText="Expense" HeaderStyle-Width="90px" />
                                <telerik:GridNumericColumn UniqueName="ProjectedAmount" DataField="ProjectedAmount" SortExpression="ProjectedAmount" DataFormatString="{0:C2}" HeaderText="Amount" HeaderStyle-Width="60px" HeaderStyle-HorizontalAlign="Right" ItemStyle-HorizontalAlign="Right" />
                                <telerik:GridDropDownColumn UniqueName="PaymentFrequency" DataField="PaymentFrequencyID" DataSourceID="dsMonitoringFrequency" ListValueField="MonitoringFrequencyID" ListTextField="MonitoringFrequencyName" HeaderText="Frequency" HeaderStyle-Width="60px" />
                                <telerik:GridDateTimeColumn UniqueName="StartDate" DataField="StartDate" SortExpression="StartDate" DataFormatString="{0:dd/MM/yyyy}" HeaderText="Start from" HeaderStyle-Width="60px" />
                                <telerik:GridDateTimeColumn UniqueName="EndDate" DataField="EndDate" SortExpression="EndDate" DataFormatString="{0:dd/MM/yyyy}" HeaderText="End at" HeaderStyle-Width="60px" />
                                <telerik:GridEditCommandColumn UniqueName="Edit" ItemStyle-CssClass="printerhide" ButtonType="ImageButton" EditImageUrl="<%$ AppSettings:GridEditButtonURL %>" HeaderStyle-Width="12px" />
                                <telerik:GridButtonColumn UniqueName="Delete" ItemStyle-CssClass="printerhide" ButtonType="ImageButton" ImageUrl="<%$ AppSettings:GridDeleteButtonURL %>" Text="Delete" CommandName="Delete" ConfirmText="Really delete this expense?" HeaderStyle-Width="12px" />
                            </Columns>
                            <EditFormSettings EditFormType="Template">
                                <FormTemplate>
                                    <table class="tableeditform">
                                        <tr>
                                            <td class="smalltext"><b>Name:</b></td>
                                            <td>
                                                <asp:TextBox ID="txtDescription" runat="server" Text='<%# Bind("Description") %>' Width="108px" TabIndex="1" />
                                            </td>
                                            <td class="smalltext"><b>Start from:</b></td>
                                            <td>
                                                <asp:TextBox ID="txtStartDate" runat="server" Text='<%# Bind("StartDate","{0:dd/MM/yyyy}") %>' Width="78px" TabIndex="5" />
                                            </td>
                                            <td>
                                                <asp:ImageButton ID="btnStartDate" runat="server" ImageUrl="~/images/small-calender.png"
                                                    CausesValidation="false" CssClass="help formimage printerhide" Title="Please choose the date of the transaction" />
                                                <act:CalendarExtender CssClass="calendar" ID="extStartDate" runat="server" TargetControlID="txtStartDate" Format="dd/MM/yyyy" PopupButtonID="btnStartDate" />
                                            </td>
                                        </tr>
                                        <tr>
                                            <td class="smalltext"><b>Amount:</b></td>
                                            <td>
                                                <asp:TextBox ID="txtAmount" runat="server" Text='<%# Bind("ProjectedAmount","{0:C2}") %>' Width="58px" TabIndex="2" />
                                            </td>
                                            <td class="smalltext"><b>End at:</b></td>
                                            <td>
                                                <asp:TextBox ID="txtEndDate" runat="server" Text='<%# Bind("EndDate","{0:dd/MM/yyyy}") %>' Width="78px" TabIndex="6" />
                                            </td>
                                            <td>
                                                <asp:ImageButton ID="btnEndDate" runat="server" ImageUrl="~/images/small-calender.png"
                                                    CausesValidation="false" CssClass="help formimage printerhide" Title="Please choose the date of the expenses transaction" />
                                                <act:CalendarExtender CssClass="calendar" ID="extEndDate" runat="server" TargetControlID="txtEndDate" Format="dd/MM/yyyy" PopupButtonID="btnEndDate" />
                                            </td>
                                        </tr>
                                        <tr>
                                            <td class="smalltext"><b>Pay Frequency:</b></td>
                                            <td>
                                                <asp:DropDownList ID="ddlPaymentFrequency" runat="server" SelectedValue='<%# Bind("PaymentFrequencyID") %>' Width="98px" TabIndex="3"
                                                    DataSourceID="dsMonitoringFrequency" DataValueField="MonitoringFrequencyID" DataTextField="MonitoringFrequencyName" />
                                                <asp:RequiredFieldValidator ID="dfvPaymentFrequency" runat="server" CssClass="ErrorMessage"
                                                    ControlToValidate="ddlPaymentFrequency" ErrorMessage="Select a expenses payment frequency."
                                                    ToolTip="Select a expenses payment frequency." Display="Dynamic" Text="*" />
                                            </td>
                                            <td class="smalltext"><b>Linked Income:</b></td>
                                            <td colspan="2">
                                                <asp:DropDownList ID="ddlIncome" runat="server" SelectedValue='<%# Bind("IncomeID") %>' Width="98px" TabIndex="7"
                                                    DataSourceID="dsClientIncome" DataValueField="IncomeID" DataTextField="IncomeShortName" />
                                            </td>
                                        </tr>
                                        <tr>
                                            <td class="smalltext"><b>Monitor Frequency:</b></td>
                                            <td>
                                                <asp:DropDownList ID="ddlMonitoringFrequency" runat="server" SelectedValue='<%# Bind("MonitoringFrequencyID") %>' Width="98px" TabIndex="4"
                                                    DataSourceID="dsMonitoringFrequency" DataValueField="MonitoringFrequencyID" DataTextField="MonitoringFrequencyName" />
                                            </td>
                                            <td class="smalltext"><b></b></td>
                                            <td colspan="2"></td>
                                        </tr>
                                        <tr>
                                            <td colspan="5" align="center">
                                                <asp:LinkButton ID="btnUpdate" runat="server" CausesValidation="true" CssClass="StandardLink help printerhide"
                                                    ToolTip="Update and save the changes you have made" CommandName='<%# (Container is GridEditFormInsertItem) ? "PerformInsert" : "Update" %>' Text='<%# (Container is GridEditFormInsertItem) ? "Confirm" : "Update" %>'
                                                    Width="100px" TabIndex="8" />
                                                <asp:LinkButton ID="btnCancel" runat="server" CausesValidation="false" CssClass="StandardLink help printerhide"
                                                    ToolTip="Cancel the changes you have made" CommandName="Cancel" Text="Cancel"
                                                    Width="100px" TabIndex="9" />
                                            </td>
                                        </tr>
                                    </table>
                                </FormTemplate>
                            </EditFormSettings>
                        </telerik:GridTableView>
                    </DetailTables>
                    <EditFormSettings EditFormType="Template">
                        <FormTemplate>
                            <table class="tableeditform">
                                <tr>
                                    <td width="150" class="standardtext">
                                        <b>Short Name:</b>
                                    </td>
                                    <td width="400">
                                        <asp:TextBox ID="txtCategoryShortName" runat="server" Text='<%# Bind("CategoryShortName") %>'
                                            MaxLength="10" Width="100" class="help" ToolTip="This will be displayed in the side menu" />
                                        (10 Characters Max.)
                                    </td>
                                </tr>
                                <tr>
                                    <td width="150" class="standardtext">
                                        <b>Full Name:</b>
                                    </td>
                                    <td width="400">
                                        <b>
                                            <asp:TextBox ID="txtCategoryName" runat="server" Text='<%# Bind("CategoryName") %>'
                                                MaxLength="255" Width="200" class="help" ToolTip="Enter the category name" />
                                        </b>
                                    </td>
                                </tr>
                                <tr>
                                    <td colspan="2" align="center">
                                        <asp:LinkButton CssClass="StandardLink printerhide" ID="btnUpdate" runat="server" Text='<%# (Container is GridEditFormInsertItem) ? "Add" : "Update" %>' CommandName='<%# (Container is GridEditFormInsertItem) ? "PerformInsert" : "Update" %>' CausesValidation="true" />

                                        <asp:LinkButton CssClass="StandardLink printerhide" ID="btnCancel" runat="server" Text="Cancel" CommandName="Cancel" CausesValidation="false" />
                                    </td>
                                </tr>
                            </table>
                        </FormTemplate>
                    </EditFormSettings>
                </MasterTableView>
            </telerik:RadGrid>
        </p>
    </div>
</asp:Panel>

Back-end:

protected void rgClientExpenseCategory_ItemDataBound(object sender, GridItemEventArgs e)
{
    if (e.Item is GridEditFormItem && e.Item.IsInEditMode && e.Item.OwnerTableView.Name == "rgExpensesCategories_Master")
    {
        GridEditFormItem editFormItem = (GridEditFormItem)e.Item;
        GridDataItem item = (GridDataItem)editFormItem.ParentItem;
        if (item != null)
        {
            m_iClientCategoryEditRow = item.ItemIndex;
        }

        // Set update button validation group
        LinkButton btnUpdate = (LinkButton)editFormItem.FindControl("btnUpdate");
        if (btnUpdate != null)
        {
            btnUpdate.ValidationGroup = ValidationGroup + "_" + e.Item.OwnerTableView.Name;
        }
    }
    if (e.Item is GridEditFormItem && e.Item.IsInEditMode && e.Item.OwnerTableView.Name == "gtvExpenses")
    {
        GridEditFormItem editFormItem = (GridEditFormItem)e.Item;

        // Set update button validation group
        LinkButton btnUpdate = (LinkButton)editFormItem.FindControl("btnUpdate");
        if (btnUpdate != null)
        {
            btnUpdate.ValidationGroup = ValidationGroup + "_" + e.Item.OwnerTableView.Name;
        }
    }
}
protected void rgClientExpenseCategory_ItemCommand(object sender, GridCommandEventArgs e)
{
    switch (e.CommandName)
    {
        case RadGrid.RebindGridCommandName:
            // Cancel insert form
            e.Item.OwnerTableView.IsItemInserted = false;
            // Cancel any edit form
            foreach (GridItem item in e.Item.OwnerTableView.Items)
            {
                if (item is GridEditableItem)
                {
                    GridEditableItem ei = item as GridEditableItem;
                    ei.Edit = false;
                }
            }
            break;
        case RadGrid.EditCommandName:
            // Cancel insert form
            e.Item.OwnerTableView.IsItemInserted = false;
            break;
        case RadGrid.InitInsertCommandName:
            // Cancel any edit form
            foreach (GridItem item in e.Item.OwnerTableView.Items)
            {
                if (item is GridEditableItem)
                {
                    GridEditableItem ei = item as GridEditableItem;
                    ei.Edit = false;
                }
            }
            break;
        default:
            break;
    }
}
protected void rgClientExpenseCategory_ItemUpdated(object sender, GridUpdatedEventArgs e)
{
    if (e.Item.OwnerTableView.Name == "gtvClientExpenses")
    {
        e.Item.Edit = false;
        rgClientExpenseCategory.MasterTableView.Rebind();
    }
}
protected void rgClientExpenseCategory_PreRender(object sender, EventArgs e)
{
    if (m_iClientCategoryEditRow != -1)
    {
        rgClientExpenseCategory.MasterTableView.Items[m_iClientCategoryEditRow].Expanded = true;
    }
}

[Lucania]

Some more information, Item_Created is never called for the GridEditformInsertItem either. I'm guessing this is why ItemCommand is never called - the form is not there, so the button isn't either. Comparing with a RadGrid directly on a page, where the ItemCreated IS called.

but I'm no closer to figuring out why the ItemCreated event never gets called.

[Tsvetina]

Hi Ross,

Is it the user control that is created on Page_PreInit? If so, have you tried loading it during a later stage of the page lifecycle - Init or Load? Do you still get the same behavior? 

Regards,
Tsvetina
the Telerik team

[Lucania]

I've tracked this down to some custom viewstate compression code I was using, based on: http://www.codeproject.com/Articles/14733/ViewState-Compression 

Not sure why that would cause this issue, but I removed it and the problem is gone.

[Aaron Whittaker]

Have anybody got this working, I am facing the same issue, I am loading the user control at page load event, but the edit/update/delete events of radgrid inside the usercontrol are not firing their corresponding events, (ie, none of the server events are being fired), it is just displaying blank user control with no radgrid at all.

[Aaron Whittaker]

When i add the usercontrol in design of the page it is working fine. 

[Aaron Whittaker]

I cannot call user control at design time as tabstri tabs are being created based on user selection:

The code is as follows:

<%@ Page Title="" Language="C#" MasterPageFile="~/Availability.Master" AutoEventWireup="true" CodeBehind="BFNRTR.aspx.cs" Inherits="BFNReportProject.BFNRTR.BFNRTR" %>

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>


<%@ Register Src="~/Availability/Controls/RTRStore.ascx" TagPrefix="uc1" TagName="RTRStore" %>
<%@ Register Src="~/Availability/Controls/RTRBlanket.ascx" TagPrefix="uc1" TagName="RTRBlanket" %>
<%@ Register Src="~/Availability/Controls/RTRWeather.ascx" TagPrefix="uc1" TagName="RTRWeather" %>
<%@ Register Src="~/Availability/Controls/RTRGrading.ascx" TagPrefix="uc1" TagName="RTRGrading" %>
<%@ Register Src="~/Availability/Controls/RTRPOS.ascx" TagPrefix="uc1" TagName="RTRPOS" %>
<%@ Register Src="~/Availability/Controls/RTRHistory.ascx" TagPrefix="uc1" TagName="RTRHistory" %>
<%@ Register Src="~/Availability/Controls/RTRAvailability.ascx" TagPrefix="uc1" TagName="RTRAvailability" %>







<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server">

    <script type="text/javascript">
        //$(document).ready(function () {
        //    var divs = $("div[id=RTRStoreDiv]")
        //    alert("count=" + divs.length);
        //    if (divs.length != 0) {
        //        if (divs.length > 1) {
        //            // alert(divs[0].innerHTML);
        //            divs.each(function (i) {
        //                $(this).attr('id', "slide" + (i + 1));

        //            });
        //            // var RemoveDiv = $("div[id=slide1]").find('.ctl00_MainContent_ctl13_ctl00_MainContent_ctl13_RadGridStorePanel');
        //            var RemoveDiv = $("#slide1 div[id=ctl00_MainContent_ctl13_ctl00_MainContent_ctl13_RadGridStorePanel]");

        //                 alert(RemoveDiv);
        //           // // RemoveDiv.parentNode.removeChild(RemoveDiv);
        //           // // RemoveDiv.remove();
        //                 if (RemoveDiv != null) {
        //                     alert("Start");
        //                     RemoveDiv.empty();
        //                     alert(RemoveDiv.innerHTML);

        //                    alert("Done");


        //            }
        //        }
        //    }

        //});



      </script>


    <div id="All">




    <div id="Heading">
        <div>
            <table style="width: 100%; height: 100%;" id="tblHeading">
                <tr class="RTRhead">
                    <td>
                        Select Customer
                    </td>
                    <td>
                        <asp:DropDownList ID="ddlCustomer" Width="100px" Height="20px" runat="server" AutoPostBack="true"></asp:DropDownList>
                    </td>
                    <td>
                        Select Group
                    </td>

                    <td>
                        <asp:DropDownList ID="ddlGroupNr" Width="100px" Height="20px" runat="server" AutoPostBack="true" style="width:100px"
            onselectedindexchanged="ddlGroupNr_SelectedIndexChanged"></asp:DropDownList>
                    </td>
                    <td>
                        Select Store
                    </td>
                    <td>
                        <asp:DropDownList ID="ddlStore" Width="100px" Height="20px" runat="server" AutoPostBack="false"></asp:DropDownList>
                    </td>
                    <td>
                        Select Farm
                    </td>
                    <td>
                        <asp:DropDownList ID="ddlFarm" Width="100px" Height="20px" AutoPostBack="false" runat="server"></asp:DropDownList>
                    </td>
                    <td>
                        <asp:Button ID="btnSave" runat="server" Text="Save Order" OnClick="btnSave_Click" />
                    </td>
                    </tr>
                <tr class="RTRhead">
                    <td >
                        Order Type
                    </td>
                    <td >
                        <asp:DropDownList ID="ddlOrderType" Width="100px" Height="20px" AutoPostBack="false" runat="server">
                            <asp:ListItem Text="Replenishment" Value="1" />
                            <asp:ListItem Text="Staged" Value="2" />
                        </asp:DropDownList>

                    </td>
                    <td>
                        Select Patch
                    </td>
                    <td>
                        <asp:DropDownList ID="ddlPatch" Width="100px" Height="20px" runat="server" AutoPostBack="true"
            onselectedindexchanged="ddlPatch_SelectedIndexChanged"  DataTextField="patch_Nr" DataValueField="patch_Nr"></asp:DropDownList>
                    </td>
                    <td>
                    </td>
                    <td>
                    </td>
                    <td>
                        Date
                    </td>
                    <td>
                        <asp:label ID="lblDate" Width="100px" Height="20px" runat="server"></asp:label>
                    </td>
                    <td>
                       <asp:Button ID="btnCreate" runat="server" Text="Create Order" OnClick="btnCreate_Click" />
                    </td>
                    <td>
                       <asp:Button ID="btnCommit" runat="server" Text="Commit Order" OnClick="btnCommit_Click" />
                    </td>
                </tr>
            </table>
        </div>

    </div>


      <div id="UpperPane">
         <telerik:RadTabStrip ID="Blanket_TabStrip" runat="server" AutoPostBack="True" MultiPageID="BlanketMultiPage"
              OnLoad="Blanket_TabStrip_Load1" Style="padding-top: 0px;padding-bottom:0px;padding-left:0px;padding-right:0px;"
               OnTabClick="Blanket_TabStrip_TabClick"

             ScrollChildren="True" SelectedIndex="0"  >
            <Tabs>
                <telerik:RadTab Text="Blanket"  Selected="true"  style="padding-top:0px;" >
                </telerik:RadTab>
            </Tabs>
             </telerik:RadTabStrip>


        <telerik:RadMultiPage ID="BlanketMultiPage" runat="server" SelectedIndex="0"  OnPageViewCreated="BlanketMultiPage_PageViewCreated"
             RenderSelectedPageOnly="true" OnLoad="BlanketMultiPage_Load" >
            <telerik:RadPageView ID="BlanketPage" Selected="true" runat="server">


            </telerik:RadPageView>

         </telerik:RadMultiPage>

    </div>

     <div id="MiddlePane"></div>
    <div id="BottomPane">
        <telerik:RadTabStrip runat="server" ID  ="LookUp_TabStrip"  MultiPageID="LookUp_MultiPage"  OnLoad="LookUp_TabStrip_Load"  OnTabClick="LookUp_TabStrip_TabClick">
            <Tabs>
                <telerik:RadTab Text="Availability" Selected="true" >
                </telerik:RadTab>
                <telerik:RadTab  Text="Point Of Sale">
                </telerik:RadTab>
                <telerik:RadTab  Text="BFN Sales History">
                </telerik:RadTab>
                <telerik:RadTab  Text="Weather" >
                </telerik:RadTab>
                <telerik:RadTab Text="Rating">
                </telerik:RadTab>
            </Tabs>
        </telerik:RadTabStrip>

        <telerik:RadMultiPage ID="LookUp_MultiPage" SelectedIndex="0" runat="server" OnPageViewCreated="LookUp_MultiPage_PageViewCreated" >
            <telerik:RadPageView ID="AvailPageView"  runat="server" Width="100%" Height="250px" >

                    </telerik:RadPageView>
            <telerik:RadPageView ID="POSPageView" runat="server" >

            </telerik:RadPageView>
            <telerik:RadPageView ID="HistPageView" runat="server"></telerik:RadPageView>
            <telerik:RadPageView ID="WeatherPageView" runat="server" ><asp:Label ID="Label3" runat="server" Text="10-Day Forecast" ></asp:Label></telerik:RadPageView>
            <telerik:RadPageView ID="GradePageView" runat="server" Width="300px" Height="362px"  ><asp:Label ID="Label6" runat="server" Text="Grading" ></asp:Label></telerik:RadPageView>

        </telerik:RadMultiPage>

    </div>
  </div>

</asp:Content>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.IO;

using Telerik.Web.UI;

using BFNReportProject.DataClasses;
using BFNReportProject.CommonClasses;
using BFNReportProject.Controls;

namespace BFNReportProject.BFNRTR
{
    public partial class BFNRTR : System.Web.UI.Page
    {
        private DataTable dt;
        DataTable storeTable;
        DataTable patchTable;
        RTRStore RTRStoreControl;
        RTRWeather RTRWeatherControl;
        RTRGrading RTRGradeControl;
        RTRPOS RTRPOSControl;
        RTRHistory RTRHistControl;
        RTRAvailability RTRAvailControl;
        RTRBlanket RTRBlanketControl;

        protected void Page_Load(object sender, EventArgs e)
        {
            BindBlanketData();
            if (!IsPostBack)
            {
                getdropdownData();

               // CreateStoreTab();

            }


        }


        #region Helper Methods


        private void CreateStoreTab()
        {
            patchTable = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), "", "PATCH");
            if (IsPostBack)
            {
                foreach (RadTab rt in Blanket_TabStrip.Tabs.ToArray())
                {
                    if (rt.Text != "Blanket")
                    {
                        Blanket_TabStrip.Tabs.Remove(rt);

                    }

                }

            }



            foreach (DataRow patchRow in patchTable.Rows)
            {
                RadTab parentTab = new RadTab();
                parentTab.Text = patchRow[0].ToString();
                parentTab.ToolTip= "Patch" + parentTab.Text;
                parentTab.Value = "Patch" + parentTab.Text;
                parentTab.ScrollChildren = true;


                Blanket_TabStrip.Tabs.Add(parentTab);

                RadPageView pageView = new RadPageView();
                //pageView.ID = patchRow[0].ToString();

                //for (int i = 0; i < BlanketMultiPage.PageViews.Count; i++)
                //{
                //    string st = BlanketMultiPage.PageViews[i].ID;
                //    RadPageView pv = BlanketMultiPage.PageViews[i];
                //    if (st == pageView.ID)
                //    {

                         Random rnd = new Random();
                         pageView.ID = patchRow[0].ToString() + rnd.Next(1000);
                    //     break;

                    //}
                //}


                BlanketMultiPage.PageViews.Add(pageView);
            }




        }



      private void getdropdownData()
        {
            try
            {

                dt = OrderInfo.GetGroupPatchLoc(0, "", "GROUP");
                ddlGroupNr.DataSource = dt;
                ddlGroupNr.DataValueField = dt.Columns[0].ToString();
                ddlGroupNr.DataTextField = dt.Columns[1].ToString();
                ddlGroupNr.DataBind();

                dt = OrderInfo.GetGroupPatchLoc(0, "", "CUST");
                ddlCustomer.DataSource = dt;
                ddlCustomer.DataValueField = dt.Columns[0].ToString();
                ddlCustomer.DataTextField = dt.Columns[1].ToString();
                ddlCustomer.DataBind();


                patchTable = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), "", "PATCH");
                ddlPatch.DataSource = patchTable;
                ddlPatch.DataTextField = patchTable.Columns[0].ToString();
                ddlPatch.DataValueField = patchTable.Columns[0].ToString();
                ddlPatch.DataBind();
                ddlPatch.Items.Insert(0, "Select ALL");

                storeTable = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), "", "GrpSTORE");
                ddlStore.DataSource = storeTable;
                ddlStore.DataTextField = storeTable.Columns[1].ToString();
                ddlStore.DataValueField = storeTable.Columns[1].ToString();
                ddlStore.DataBind();
                ddlStore.Items.Insert(0, "Select ALL");



                dt = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), ddlPatch.SelectedValue, "LOC");
                ddlFarm.DataSource = dt;
                ddlFarm.DataTextField = dt.Columns[0].ToString();
                ddlFarm.DataValueField = dt.Columns[0].ToString();
                ddlFarm.DataBind();


                lblDate.Text = System.DateTime.Now.ToShortDateString();



           }
            catch (Exception ex)
            {
                HttpContext.Current.Response.Write(ex.Message);

            }

        }

      private void BindAvailData()
      {
          RTRAvailControl = (RTRAvailability)Page.LoadControl("~/Availability/Controls/RTRAvailability.ascx");

          RTRAvailControl.GroupNr = ddlGroupNr.SelectedValue;
          RTRAvailControl.Customer = Convert.ToInt32(ddlCustomer.SelectedValue);
          //if (Session["store"] != null && Blanket_TabStrip.SelectedTab.Text != "Blanket")
          //    RTRAvailControl.Store = (String)Session["store"];
          if (Blanket_TabStrip.SelectedTab.SelectedTab != null)
              RTRAvailControl.Store = Blanket_TabStrip.SelectedTab.SelectedTab.Text;
          else
              RTRAvailControl.Store = null;

          RTRAvailControl.Patch = ddlPatch.SelectedValue == "Select ALL" ? null : ddlPatch.SelectedValue;
          RTRAvailControl.Farm = ddlFarm.SelectedValue;
          RTRAvailControl.OrderType = ddlOrderType.SelectedValue;
          AvailPageView.Controls.Add(RTRAvailControl);
      }
      private void BindWeatherData()
      {
          RTRWeatherControl = (RTRWeather)Page.LoadControl("~/Availability/Controls/RTRWeather.ascx");

          RTRWeatherControl.GroupNr = ddlGroupNr.SelectedValue;
          RTRWeatherControl.Customer = Convert.ToInt32(ddlCustomer.SelectedValue);
          //if (Session["store"] != null && Blanket_TabStrip.SelectedTab.Text != "Blanket")
          //    RTRWeatherControl.Store = (String)Session["store"];
          if (Blanket_TabStrip.SelectedTab.SelectedTab != null)
              RTRWeatherControl.Store = Blanket_TabStrip.SelectedTab.SelectedTab.Text;
          else
              RTRWeatherControl.Store = null;

          RTRWeatherControl.Patch = ddlPatch.SelectedValue == "Select ALL" ? null : ddlPatch.SelectedValue;
          RTRWeatherControl.Farm = ddlFarm.SelectedValue;
          RTRWeatherControl.OrderType = ddlOrderType.SelectedValue;


          WeatherPageView.Controls.Add(RTRWeatherControl);

      }
      private void BindGradingData()
      {
          RTRGradeControl = (RTRGrading)Page.LoadControl("~/Availability/Controls/RTRGrading.ascx");

          RTRGradeControl.GroupNr = ddlGroupNr.SelectedValue;
          RTRGradeControl.Customer = Convert.ToInt32(ddlCustomer.SelectedValue);
          //if (Session["store"] != null && Blanket_TabStrip.SelectedTab.Text != "Blanket")
          //    RTRGradeControl.Store = (String)Session["store"];
          if (Blanket_TabStrip.SelectedTab.SelectedTab != null)
              RTRGradeControl.Store = Blanket_TabStrip.SelectedTab.SelectedTab.Text;
          else
              RTRGradeControl.Store = null;


          RTRGradeControl.Patch = ddlPatch.SelectedValue == "Select ALL" ? null : ddlPatch.SelectedValue;
          RTRGradeControl.Farm = ddlFarm.SelectedValue;
          RTRGradeControl.OrderType = ddlOrderType.SelectedValue;

          GradePageView.Controls.Add(RTRGradeControl);

      }

      private void BindPOSData(string BlanketSelected)
      {
          RTRPOSControl = (RTRPOS)Page.LoadControl("~/Availability/Controls/RTRPOS.ascx");

          RTRPOSControl.GroupNr = ddlGroupNr.SelectedValue;
          RTRPOSControl.Customer = Convert.ToInt32(ddlCustomer.SelectedValue);
          if (Session["store"] != null && Blanket_TabStrip.SelectedTab.Text != "Blanket")
          {
              if(Blanket_TabStrip.SelectedTab.SelectedTab != null)
                  RTRPOSControl.Store = (String)Session["store"];
          }
          else
              RTRPOSControl.Store = null;

          RTRPOSControl.BlanketSelected = BlanketSelected == "Blanket" ? true : false;

          RTRPOSControl.Patch = ddlPatch.SelectedValue == "Select ALL" ? null : ddlPatch.SelectedValue;
          RTRPOSControl.Farm = ddlFarm.SelectedValue;
          RTRPOSControl.OrderType = ddlOrderType.SelectedValue;

          POSPageView.Controls.Add(RTRPOSControl);

      }
      private void BindHistoryData(string BlanketSelected)
      {
          RTRHistControl = (RTRHistory)Page.LoadControl("~/Availability/Controls/RTRHistory.ascx");

          RTRHistControl.GroupNr = ddlGroupNr.SelectedValue;
          RTRHistControl.Customer = Convert.ToInt32(ddlCustomer.SelectedValue);
          //if (Session["store"] != null && Blanket_TabStrip.SelectedTab.Text != "Blanket")
          //    RTRHistControl.Store = (String)Session["store"];
          if (Blanket_TabStrip.SelectedTab.SelectedTab != null)
              RTRHistControl.Store = Blanket_TabStrip.SelectedTab.SelectedTab.Text;
          else
              RTRHistControl.Store = null;

          RTRHistControl.BlanketSelected = BlanketSelected == "Blanket" ? true : false;

          RTRHistControl.Patch = ddlPatch.SelectedValue == "Select ALL" ? null : ddlPatch.SelectedValue;
          RTRHistControl.Farm = ddlFarm.SelectedValue;
          RTRHistControl.OrderType = ddlOrderType.SelectedValue;

          HistPageView.Controls.Add(RTRHistControl);

      }

      private void BindBlanketData()
      {
          RTRBlanketControl = (RTRBlanket)Page.LoadControl("~/Availability/Controls/RTRBlanket.ascx");

          RTRBlanketControl.GroupNr = ddlGroupNr.SelectedValue;
          RTRBlanketControl.Customer = ddlCustomer.SelectedValue;
         // RTRHistControl.Store = ddlStore.SelectedValue;
          RTRBlanketControl.Patch = ddlPatch.SelectedValue;
          RTRBlanketControl.Farm = ddlFarm.SelectedValue;
          RTRBlanketControl.OrderType = ddlOrderType.SelectedValue;
          RTRBlanketControl.bindGrid();
          BlanketPage.Controls.Add(RTRBlanketControl);
      }






        #endregion

      protected void ddlGroupNr_SelectedIndexChanged(object sender, EventArgs e)
        {
            dt = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), "", "PATCH");

            ddlPatch.DataSource = dt;
            ddlPatch.DataTextField = dt.Columns[0].ToString();
            ddlPatch.DataValueField = dt.Columns[0].ToString();
            ddlPatch.DataBind();
            ddlPatch.Items.Insert(0, "Select ALL");
            BlanketPage.Visible = false;

            storeTable = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), ddlGroupNr.SelectedValue, "GrpSTORE");
            ddlStore.DataSource = storeTable;
            ddlStore.DataTextField = storeTable.Columns[1].ToString();
            ddlStore.DataValueField = storeTable.Columns[1].ToString();
            ddlStore.Items.Insert(0, "Select ALL");
            ddlStore.DataBind();

        }



        protected void ddlPatch_SelectedIndexChanged(object sender, EventArgs e)
        {
            storeTable = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), ddlPatch.SelectedValue, "STORE");
            ddlStore.DataSource = storeTable;
            ddlStore.DataTextField = storeTable.Columns[1].ToString();
            ddlStore.DataValueField = storeTable.Columns[1].ToString();
            ddlStore.DataBind();
            ddlStore.Items.Insert(0, "Select ALL");
            CreateStoreTab();
        }

        protected void LookUp_MultiPage_PageViewCreated(object sender, RadMultiPageEventArgs e)
        {

        }


        protected void LookUp_TabStrip_TabClick(object sender, RadTabStripEventArgs e)
        {
            string selectedTab = e.Tab.Text;
            switch (selectedTab)
            {
                case "Availability":
                    {
                        BindAvailData();
                        break;
                    }

                case "Point Of Sale":
                    {
                        BindPOSData(Blanket_TabStrip.SelectedTab.Text);
                        break;
                    }
                case "BFN Sales History":
                    {
                        BindHistoryData(Blanket_TabStrip.SelectedTab.Text);
                        break;
                    }

                case "Weather":
                    {
                        BindWeatherData();
                        break;
                    }
                case "Rating":
                    {
                        BindGradingData();
                        break;
                    }

            }
            if (Blanket_TabStrip.SelectedTab.SelectedTab != null)
            {

                RTRStoreControl = (RTRStore)Page.LoadControl("~/Availability/Controls/RTRStore.ascx");
                RTRStoreControl.GroupNr = ddlGroupNr.SelectedValue;
                RTRStoreControl.Customer = ddlCustomer.SelectedValue;
                RTRStoreControl.Store = (string)Session["store"];
                RTRStoreControl.Patch = ddlPatch.SelectedValue;
                RTRStoreControl.Farm = ddlFarm.SelectedValue;
                RTRStoreControl.OrderType = ddlOrderType.SelectedValue;
                RTRStoreControl.table = (DataTable)Session["BlanketTable"];
                // bool IsStoreBinded = RTRStoreControl.Bind;

                RadPageView selectedpageView = Blanket_TabStrip.SelectedTab.SelectedTab.PageView;

                selectedpageView.Controls.Add(RTRStoreControl);
            }
            else if (Blanket_TabStrip.SelectedTab.Text == "Blanket")
                BindBlanketData();



        }

        protected void LookUp_TabStrip_Load(object sender, EventArgs e)
        {




        }


        protected void imgbtn_Click(object sender, ImageClickEventArgs e)
        {
            ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "MyScript", "alert('Are you sure you want to delete this item !!');", true);

        }

        protected void Blanket_TabStrip_Load(object sender, EventArgs e)
        {


        }

        protected void BlanketMultiPage_PageViewCreated(object sender, RadMultiPageEventArgs e)
        {

           //RTRStoreControl =(RTRStore) Page.LoadControl("~/Availability/Controls/RTRStore.ascx");

           // RTRStoreControl.GroupNr = ddlGroupNr.SelectedValue;
           // RTRStoreControl.Customer = ddlCustomer.SelectedValue;
           // if(Session["store"] != null)
           //     RTRStoreControl.Store = (String)Session["store"];
           // else
           //     RTRStoreControl.Store = ddlStore.SelectedValue;


           // RTRStoreControl.Patch = ddlPatch.SelectedValue;
           // RTRStoreControl.Farm = ddlFarm.SelectedValue;
           // RTRStoreControl.OrderType = ddlOrderType.SelectedValue;
           // RTRStoreControl.table = (DataTable)Session["BlanketTable"];
           // e.PageView.Controls.Add(RTRStoreControl);


        }

        protected void Blanket_TabStrip_Load1(object sender, EventArgs e)
        {


        }

        protected void Blanket_TabStrip_TabClick(object sender, RadTabStripEventArgs e)
        {
            if (e.Tab.Text != "Blanket")
            {
                if (e.Tab.ToolTip.StartsWith("Patch") && !e.Tab.HasControls())
                {
                    bool t = e.Tab.HasControls();
                    storeTable = OrderInfo.GetGroupPatchLoc(Convert.ToInt32(ddlGroupNr.SelectedValue), e.Tab.Text.Trim(), "STORE");
                    string txt = e.Tab.Text;
                    foreach (DataRow storeRow in storeTable.Rows)
                    {
                        RadTab childtab = new RadTab();
                        RadTab ParentTab = e.Tab;
                        childtab.Text = storeRow[1].ToString();
                        childtab.Value = "Store" + childtab.Text;
                        childtab.ToolTip = "Store" + childtab.Text;
                        ParentTab.Tabs.Add(childtab);

                        RadPageView pageView = new RadPageView();

                        Random rnd = new Random();
                        pageView.ID = storeRow[1].ToString() + rnd.Next(1000);
                        BlanketMultiPage.PageViews.Add(pageView);
                    }
                }

                else
                {
                    e.Tab.Selected = true;
                    RTRStoreControl = (RTRStore)Page.LoadControl("~/Availability/Controls/RTRStore.ascx");
                    RTRStoreControl.GroupNr = ddlGroupNr.SelectedValue;
                    RTRStoreControl.Customer = ddlCustomer.SelectedValue;
                    RTRStoreControl.Store = e.Tab.Text;
                    Session["store"] = e.Tab.Text;
                    RTRStoreControl.Patch = ddlPatch.SelectedValue;
                    RTRStoreControl.Farm = ddlFarm.SelectedValue;
                    RTRStoreControl.OrderType = ddlOrderType.SelectedValue;
                    RTRStoreControl.table = (DataTable)Session["BlanketTable"];
                    // bool IsBinded = RTRStoreControl.Bind;
                    e.Tab.PageView.Controls.Add(RTRStoreControl);
                    // Page.ClientScript.RegisterStartupScript(this.GetType(), "lblscript", "<script type=\"text/JavaScript\" language=\"javascript\" language=\"javascript\">test();</script>");
                    //BindWeatherData(e.Tab.text);
                    //BindGradingData(e.Tab.text);
                    //BindPOSData(Blanket_TabStrip.SelectedTab.Text, e.Tab.text);
                    //BindHistoryData(Blanket_TabStrip.SelectedTab.Text, e.Tab.text);
                    //BindAvailData(e.Tab.text);


                }

            }
            else
            {
                BindBlanketData();
            }

            if (!e.Tab.ToolTip.StartsWith("Patch"))
            {
                string selectedTab = LookUp_TabStrip.SelectedTab.Text;
                switch (selectedTab)
                {
                    case "Availability":
                        {
                            BindAvailData();
                            break;
                        }

                    case "Point Of Sale":
                        {
                            BindPOSData(Blanket_TabStrip.SelectedTab.Text);
                            break;
                        }
                    case "BFN Sales History":
                        {
                            BindHistoryData(Blanket_TabStrip.SelectedTab.Text);
                            break;
                        }

                    case "Weather":
                        {
                            BindWeatherData();
                            break;
                        }
                    case "Rating":
                        {
                            BindGradingData();
                            break;
                        }

                }
            }


        }

        protected void BlanketMultiPage_Load(object sender, EventArgs e)
        {


        }

        protected void btnCommit_Click(object sender, EventArgs e)
        {
            //if (Session["XMLTable"] != null)
            //{
            //    string tabString = BFNReportProject.CommonClasses.Helper.ToCSV((DataTable)Session["XMLTable"],"  ", false);
            //    File.WriteAllText(@"c:\XMLFolder\Replenishment.txt", tabString, System.Text.Encoding.Default);
            //}

            Session["XMLTable"] = null;
            Session["BlanketTable"] = null;
            ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "myalert", "alert('" + "Order Completed" + "');", true);
        }

        protected void btnSave_Click(object sender, EventArgs e)
        {
            //if (Session["XMLTable"] != null)
            //    dt = (DataTable)Session["XMLTable"];
            //System.IO.StringWriter writer = new System.IO.StringWriter();

            ////notice that we're ignoring the schema so we get clean XML back
            ////you can change the write mode as needed to get your result
            //dt.WriteXml(writer, XmlWriteMode.IgnoreSchema, true);

            //string dataTableXml = writer.ToString();
            //// save the XML in database.
            //dt.WriteXml(@"c:\XMLFolder\Replenishment.xml");

            ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "myalert", "alert('" + "Order Saved" + "');", true);

        }

         protected void btnCreate_Click(object sender, EventArgs e)
        {
            CreateStoreTab();
            BindBlanketData();
            string selectedTab = LookUp_TabStrip.SelectedTab.Text;
            switch (selectedTab)
            {
                case "Availability":
                    {
                        BindAvailData();
                        break;
                    }

                case "Point Of Sale":
                    {
                        BindPOSData(Blanket_TabStrip.SelectedTab.Text);
                        break;
                    }
                case "BFN Sales History":
                    {
                        BindHistoryData(Blanket_TabStrip.SelectedTab.Text);
                        break;
                    }

                case "Weather" :
                    {
                        BindWeatherData();
                        break;
                    }
                case "Rating" :
                    {
                        BindGradingData();
                        break;
                    }

            }

          //  BindPOSData(string.Empty);
          //  BindWeatherData();
         //   BindHistoryData(string.Empty);
          //  BindGradingData();


        }


}
}

[Daniel]

Hello Aaron,

You have to recreate the control if you want it to be working properly after postback. This one is similar:
Issue with dynamically loading a user control on button click

Kind regards,
Daniel
the Telerik team