DropDownList as EditorTemplate with big data

[CPS]

I use a DropDownList as an EditorTemplate in a Grid.

The problem is, that the DDL has to display several thousand entries (products).

I tried to set the PageSize of the DataSource and handle the Filter-Event. This works fine so far.  The DDL opens very fast and I can search (filter) and then select an entry, that is not visible in the list at the beginning.

This works fine for adding a new record.

But when I want to edit an existing record in the grid I get problems. When the editor opens and the value is not in the select list of the DDL, it is not selected (also not displayed) and the value of the DDL is set to null.

This behavior makes sense to me.

When I remove the PageSize from the DataSource everythings works fine. But it takes to long to open the DDL. That's why I need another solution.

I also tried the virtualization. But the problem stays the same.

Does anyone have an idea how I can solve this?

Maybe another control? Finally the user should be able to search and select a product on an easy way.

I am grateful for any idea.

[CPS]

I found a solution. 

No need for further investigations.