ASPxGridView cascading ComboBox in the Filter Row

See also:
112

Hello Vest,
I just looked at E112 and it uses a totally different method than the Q155269.zip file. The Q155269.zip solution has the following problems:
  1. Selecting a Country automatically selects the first City in the Cities combobox but it only filters on the Country selection. So the filter is acting like the City combobox is blank which it should be.
  2. Selecting a City does filter on the City seletion but then the Cities Combobox text changes back to the first City in the list.
The E112 solution does not suffer from either of these problems. However, I need to have the same cascading comboboxes in Edit Mode and with the Clear Filter Button. The E112 solution has the following problems when I enabled editing and enabled the Clear Filter Button:
  1. Select a Country in the Filter then clear the Filter. The City combobox in the Filter is still populated (because we didn't change the session variable).
  2. Now edit one of the rows and the City combobox in the Edit Form is populated with the cities from the Country originally selected in the Filter in problem 1 (again because we didn't change the session variable).
It seems like a few more events (like entering edit mode and when Clear Filte click) need to change the session variable. What is the best way to handle these problems? I also need to have updating enabled; will there be problems with that? Will more events need to be handled?
Thanks,
     Jeff

Hello Jeff,
Thank you for the detailed feedback. Yes, I know that my example might not work properly for the filter row. Actually it is hard to implement cascaded comboboxes in the filter row. You should always concern about the following situations:

1. when the first combobox is changed, you should bind the second combobox in its callback.
2. when the first combobox is changed, the ASPxGridView performs filtering, and then it recreates its hierarchy.
3. when the second combobox is populated, it might perform the filtering again, because its selected item might be changed, and the grid will catch this.
   Every page callback, or grid's callbacks recreates the page hierarchy. That is why my solution might not work completely :(
   Maybe you can try the attached example, and if the filtering works fine simply implement the cascaded feature via ASPxComboBox controls within templates.
   Thanks,
   Vest