[Solved] ForeignKeyColumn An item with the same key has already been added

[StevenDale]

ASP.Net MVC 2012 Q1
I have a .aspx page that contains a Telerik Grid. Within the details view of my grid, I have a TabStrip. Within each tab there is a Telerik Grid. Within each Grid I have a ForeignKey column. In the first Grid the ForeignKey column points to ViewData["AddressTypes"]. In the second Grid the ForeignKey column points to ViewData["EmailAddressTypes"]. Both of these lists (i.e. ViewData["AddressTypes"] and ViewData["EmailAddressTypes"]) contain the same elements and therefore have the same Ids. When I run the application I get the following error and stack trace. Further below is my markup.

NOTE: This error appears to be the ForeignKeyColumns using same lists in conjunction with having Edit and Delete Commands. If I comment out either the foreignKey columns or the command columns then I get no error.

An item with the same key has already been added.

   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at System.Web.Mvc.ViewDataDictionary.Add(String key, Object value)
   at Telerik.Web.Mvc.UI.GridForeignKeyColumn`2.AppendSelectList(IDictionary`2 viewData, Object dataItem) in f:\114\Griffin\Trunk Full\Sources\Source\Telerik.Web.Mvc\UI\Grid\Columns\GridForeignKeyColumn.cs:line 96

.DetailView(details2 => details2.ClientTemplate(
                                    Html.Telerik().TabStrip()
                                    .Name("TabStrip_<#= Id #>")
                                    .SelectedIndex(0)
                                    .Items(items2 =>
                                    {
                                        items2.Add().Text("Addresses").Content
                                        (
                                            Html.Telerik().Grid<AddressModel>().Name("UserAddress_<#= Id #>")
                                            .DataKeys(keys => { keys.Add(a => a.Id).RouteKey("addressId"); keys.Add(a => a.OwnerId).RouteKey("addressOwnerId"); })
                                            .Columns(columns =>
                                            {
                                                columns.ForeignKey(a => a.TypeId, (IEnumerable)ViewData["AddressTypes"], "Id", "Name").Width(100);
                                                columns.Bound(a => a.AddressLine1).Width(200);
                                                columns.Bound(a => a.AddressLine2).Width(200);
                                                columns.Bound(a => a.City).Width(120);
                                                columns.ForeignKey(a => a.StateId, (IEnumerable)ViewData["States"], "Id", "Name").Width(100);
                                                columns.Bound(a => a.ZipCode).Width(100);
                                                columns.Command(commands => { commands.Edit(); commands.Delete(); }).Width(100);
                                            })

                                            .DataBinding(dataBinding => dataBinding.Ajax()
                                            .Select("AddressAjax", "Group", new { organizationalUnitId = "<#= Id #>" })
                                            .Insert("InsertAddress", "Group")
                                            .Update("SaveAddress", "Group")
                                            .Delete("DeleteAddress", "Group")
                                            )
                                            .Pageable()
                                            .Sortable()
                                            .Filterable()
                                            .ToHtmlString()
                                        );
                                        items2.Add().Text("Email").Content
                                        (
                                            Html.Telerik().Grid<EmailModel>().Name("UserEmailAddress_<#= Id #>")
                                            .DataKeys(keys => { keys.Add(e => e.Id).RouteKey("emailId"); keys.Add(e => e.OwnerId).RouteKey("ownerId"); })
                                            .Columns(columns =>
                                            {
                                                columns.Bound(e => e.EmailAddress).Width(200);
                                                columns.ForeignKey(e => e.TypeId, (IEnumerable)ViewData["EmailAddressTypes"], "Id", "Name").Width(100);
                                                columns.Command(commands => { commands.Edit(); commands.Delete(); }).Width(100);
                                            })
                                            .DataBinding(dataBinding => dataBinding.Ajax()
                                                .Select("EmailAddressAjax", "Group", new { organizationalUnitId = "<#= Id #>" })
                                                .Insert("InsertEmailAddress", "Group")
                                                .Update("SaveEmailAddress", "Group")
                                                .Delete("DeleteEmailAddress", "Group")
                                            )
                                            .Pageable()
                                            .Sortable()
                                            .Filterable()
                                            .ToHtmlString()
                                        );
                                    })
                                    .ToHtmlString()
                                    ))

Thanks,

[Daniel]

Hello Billy,

I posted my answer in the support ticket you have opened. For convenience, I am pasting my reply below:

*******************************************************************************************************************
The problem occurs because the properties have the same name. So when the Grid tries to add the "TypeId_Data" key to the ViewDataDictionary an exception is thrown. The easiest way to workaround this limitation is to remove the item from the ViewContext ViewDataDictionary before the ForeignKey column definition in the second Grid. For example:

columns.Bound(e => e.EmailAddress).Width(200);

this.ViewContext.ViewData.Remove("TypeId_Data");

columns.ForeignKey(e => e.TypeId, (IEnumerable)ViewData["EmailAddressTypes"], "Id", "Name").Width(100);

*******************************************************************************************************************

Kind regards,
Daniel
the Telerik team