I want to use a method that refreshes the item in the Menu while it is open. 

The menu gets the focus off other components such as TextBox and NumericTextBox on every keystroke in the input area. 

I would expect that setting HasChildren to false would prevent sub-menus and expand arrows from the current item. It does not. I am using hierarchical data binding.

If the collection you pass to the Menu Data parameter is null or empty, you will get an exception like this

System.ArgumentNullException: Value cannot be null. (Parameter 'source')
   at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Telerik.Blazor.Components.TelerikMenu`1.<BuildRenderTree>b__0_0(RenderTreeBuilder __builder2)

Using the demo on https://demos.telerik.com/blazor-ui/menu/index if you select Item 1 with the left mouse button, both Item 1 and Item 2 drop downs open, see attached images

 

 

I'd like to be able to build a custom menu that contains other controls and that is similar to the ones on the grid column menu but usable from anywhere.

The closest I can get with Telerik controls is the Menu with custom templates, but ideally I could anchor the menu to a button that has a custom icon or text (vs hovering over a hyperlink)