i have an dropdownlist in my toolbar from my grid. i want to populate the dropdownlist with the column names of that grid. any suggestions? 

```
 @(Html.Kendo().Grid(Model)    
.Name("Grid")
.Columns(columns =>
{
    columns.Bound(p => p.Name).Groupable(false);
    columns.Bound(p => p.FullName);
    //columns.Command(commandAction: command => command.Custom("ViewDetails").Click("showDetails"));
})

.DataSource(dataSource => dataSource
    .Ajax()
    .Read(read => read.Action("Customers_read", "jvIndex"))

    .PageSize(1)
)

.ToolBar(toolbar =>
{

    toolbar.Template(@<text>
                          <div class="toolbar">

                              <input type="text" class="k-input"/>
                                  @(Html.Kendo().DropDownList()
                                  .Name("categories")
                                  .OptionLabel("All")
                                  .DataTextField("")
                                  .DataValueField("")

                                  .Events(e=>e.Change("categoriesChange"))
                                  .BindTo()
                                  )

                               <button class="k-button" id="get">Filter</button>

                          </div>
                      </text>);

})
.HtmlAttributes(new { style = "height: 430px" })
.Pageable()
.Sortable()
.Scrollable()
.DataSource(dataSource => dataSource
    .Ajax()
    .PageSize(20)
    .ServerOperation(false)
    .Model(model => model.Id(p => p.Name))
    .Read("ToolbarTemplate_Read", "jvIndex")
)

```

)
)