[Solved] Trying to reorder items with drag/drop - why is DestDataItem null?

[Kelly]

I am trying to reorder items with drag/drop - but e.DestDataItem is null in my RadGrid1_RowDrop event and I can't figure out why.

The example works for me (e.DestDataItem is not null), but I can't tell what the difference is between my code and the example.  If someone could help me out I would greatly appreciate it.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using Telerik.Web.UI;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using NewMillennium;
using NewMillennium.DataAccess;

public partial class Admin_UserControls_OrderFields : MillenniumUserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {
        RadGrid1.Skin = Common.GridSkin;
        if (!Page.IsPostBack)
        {
            WebProgramFieldSessionData.ClearSessionData();
            RefreshGrid();
        }
    }

    private void RefreshGrid()
    {
        RadGrid1.MasterTableView.EditMode = GridEditMode.InPlace;
        RadGrid1.DataSource = WebProgramFieldSessionData.GetWebProgramFields(ProjectProgramID);
        RadGrid1.Rebind();
        EditAllRows();
    }

    protected void EditAllRows()
    {
        foreach (GridDataItem item in RadGrid1.Items)
            item.Edit = true;
        RadGrid1.Rebind();
    }


    protected void RadGrid1_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
    {
        RadGrid1.DataSource = WebProgramFieldSessionData.GetWebProgramFields(ProjectProgramID);
    }

    protected void RadGrid1_ItemCommand(object sender, GridCommandEventArgs e)
    {
        if (e.CommandName == "Refresh")
        {
            SaveChangesInSession();
        }
    }

    public void SaveChangesInSession()
    {
        foreach (GridItem item in RadGrid1.Items)
        {
            if (item is GridDataItem && item.IsInEditMode)
            {
                GridDataItem gridDataItem = item as GridDataItem;
                int index = gridDataItem.DataSetIndex;
                WebProgramField field = new WebProgramField(WebProgramFieldSessionData.WebProgramFields.Rows[index]);
                field.FieldLabel = (gridDataItem["FieldLabel"].Controls[1] as TextBox).Text;
                field.SortOrder = Convert.ToInt32((gridDataItem["SortOrder"].Controls[1] as TextBox).Text);
                field.Visible = (gridDataItem["Visible"].Controls[0] as CheckBox).Checked;
                field.Required = (gridDataItem["Required"].Controls[0] as CheckBox).Checked;
                WebProgramFieldSessionData.Update(gridDataItem.DataSetIndex, field);
            }
        }
        WebProgramFieldSessionData.UpdateSortOrder();
        RefreshGrid();
    }

    public void SaveChangesInDatabase()
    {
        WebProgramFieldSessionData.SaveChangesInDatabase();
    }

    protected void RadGrid1_RowDrop(object sender, GridDragDropEventArgs e)
    {
        if (string.IsNullOrEmpty(e.HtmlElement))
        {
            if (e.DestDataItem != null && e.DestDataItem.OwnerGridID == RadGrid1.ClientID)
            {
                //TODO: do stuff here
            }
        }
    }

    private int ProjectProgramID
    {
        get
        {
            try
            {
                return Convert.ToInt32(Request.QueryString["ProjectProgramID"]);
            }
            catch
            {
                throw new ArgumentException("WebProgramFields.ascx requires a valid ProjectProgramID in the querystring.");
            }
        }
    }
}

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="WebProgramFields.ascx.cs"
    Inherits="Admin_UserControls_OrderFields" %>
<%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI" %>
<asp:Label runat="server" ID="lblTitle"></asp:Label>
<telerik:RadGrid ID="RadGrid1" runat="server" GridLines="None" AllowSorting="False"
    AutoGenerateColumns="False" AllowMultiRowEdit="true" AllowMultiRowSelection="true"
    OnNeedDataSource="RadGrid1_NeedDataSource" OnItemCommand="RadGrid1_ItemCommand"
    OnRowDrop="RadGrid1_RowDrop">
    <PagerStyle Mode="NextPrevAndNumeric"></PagerStyle>
    <ClientSettings AllowRowsDragDrop="True">
        <Selecting AllowRowSelect="True" EnableDragToSelectRows="true" />
    </ClientSettings>
    <MasterTableView CommandItemDisplay="Top" DataKeyNames="FieldID" AutoGenerateColumns="False">
        <CommandItemTemplate>
            <div style="padding-bottom: 8px">
                <asp:LinkButton ID="RefreshButton" runat="server" CommandName="Refresh" OnClientClick="suppressConfirmation()"><img class="middle" alt="" src="../Images/Telerik/Refresh.gif" /> Refresh&nbsp;</asp:LinkButton>
            </div>
        </CommandItemTemplate>
        <Columns>
            <telerik:GridBoundColumn SortExpression="DefaultFieldLabel" HeaderText="Field Label"
                HeaderButtonType="TextButton" DataField="DefaultFieldLabel" ReadOnly="true">
                <HeaderStyle HorizontalAlign="Left" />
            </telerik:GridBoundColumn>
            <telerik:GridCheckBoxColumn SortExpression="FieldVisible" HeaderText="Visible" HeaderButtonType="TextButton"
                DataField="FieldVisible" UniqueName="Visible" DataType="System.Boolean">
                <HeaderStyle Width="50px" HorizontalAlign="center" />
                <ItemStyle HorizontalAlign="center" />
            </telerik:GridCheckBoxColumn>
            <telerik:GridCheckBoxColumn SortExpression="FieldRequired" HeaderText="Required"
                HeaderButtonType="TextButton" DataField="FieldRequired" UniqueName="Required"
                DataType="System.Boolean">
                <HeaderStyle Width="50px" HorizontalAlign="center" />
                <ItemStyle HorizontalAlign="center" />
            </telerik:GridCheckBoxColumn>
            <telerik:GridTemplateColumn SortExpression="SortOrder" HeaderText="Sort Order" HeaderButtonType="TextButton"
                DataField="SortOrder" UniqueName="SortOrder">
                <HeaderStyle HorizontalAlign="center" />
                <ItemStyle HorizontalAlign="center" Width="80px" />
                <ItemTemplate>
                    <asp:TextBox ID="SortOrder" runat="server" Width="80px" Text='<%# Bind("SortOrder") %>'></asp:TextBox>
                </ItemTemplate>
            </telerik:GridTemplateColumn>
            <telerik:GridTemplateColumn SortExpression="FieldLabel" HeaderText="Alternate Field Label"
                HeaderButtonType="TextButton" DataField="FieldLabel" UniqueName="FieldLabel">
                <HeaderStyle HorizontalAlign="center" />
                <ItemStyle HorizontalAlign="center" Width="80px" />
                <ItemTemplate>
                    <asp:TextBox ID="FieldLabel" runat="server" Width="200px" Text='<%# Bind("FieldLabel") %>'></asp:TextBox>
                </ItemTemplate>
            </telerik:GridTemplateColumn>
        </Columns>
    </MasterTableView>
</telerik:RadGrid>

    public class WebProgramFieldSessionData
    {
        public static DataTable GetWebProgramFields(int projectProgramID)
        {
            ProjectProgramID = projectProgramID;
            return WebProgramFields;
        }

        public static void ClearSessionData()
        {
            System.Web.HttpContext.Current.Session["WebProgramFields"] = null;
            System.Web.HttpContext.Current.Session["WebProgramFields_ProjectProgramID"] = null;
        }

        public static DataTable WebProgramFields
        {
            get
            {
                try
                {
                    if (System.Web.HttpContext.Current.Session["WebProgramFields"] != null)
                    {
                        return System.Web.HttpContext.Current.Session["WebProgramFields"] as DataTable;
                    }
                    else
                    {
                        DataTable t = WebProgramField.GetWebProgramFieldSettingsAsDataTable(ProjectProgramID);
                        System.Web.HttpContext.Current.Session["WebProgramFields"] = t;
                        return t;
                    }
                }
                catch (Exception ex)
                {
                    throw new ApplicationException("The web program fields could not be initialized because of an error: " + ex.Message);
                }
            }
        }

        public static int ProjectProgramID
        {
            get
            {
                if (System.Web.HttpContext.Current.Session["WebProgramFields_ProjectProgramID"] == null)
                    System.Web.HttpContext.Current.Session["WebProgramFields_ProjectProgramID"] = 0;
                return Convert.ToInt32(System.Web.HttpContext.Current.Session["WebProgramFields_ProjectProgramID"]);
            }
            set
            {
                System.Web.HttpContext.Current.Session["WebProgramFields_ProjectProgramID"] = value;
            }
        }

        /// <summary>
        /// Updates a row in session (not in the database).
        /// </summary>
        public static void Update(int index, WebProgramField field)
        {
            DataRow row = WebProgramFields.Rows[index];
            row["FieldLabel"] = field.FieldLabel;
            row["SortOrder"] = field.SortOrder;
            row["FieldVisible"] = field.Visible;
            row["FieldRequired"] = field.Required;
        }

        /// <summary>
        /// Corrects the sort order for all items in session.
        /// This method does not save anything in the database.
        /// </summary>
        public static void UpdateSortOrder()
        {
            WebProgramFields.DefaultView.Sort = "SortOrder asc";
            int counter = 1;
            foreach (DataRowView row in WebProgramFields.DefaultView)
            {
                row["SortOrder"] = counter;
                counter++;
            }
        }

        public static void SaveChangesInDatabase()
        {
            foreach (DataRow row in WebProgramFields.Rows)
            {
                WebProgramField field = new WebProgramField(row);
                field.Save();
            }
        }
    }

[Adam Nelson]

I had the same issue, found this post http://www.telerik.com/community/forums/thread/b311D-bdegmm.aspx 

its an issue with the grid being in a content page or user control.

[Adam Nelson]

i think it should be fixed in the latest hotfix Ver. 2008 1 515