One suggestion would be performing these functionalities on server side.
You can get reference to the GridDropdownColumn in the ItemCreated event and attach the SelectedIndexChanged event for the control. Now in the event handler, access the second dropdownlist control and populate it accordingly.
You can access the second dropdownlist control by accessingt the editform (using NamingContainer property of dropdown) and then by using the FindControl() method.
Are you saying that there is no means of accomplishing this task with a parameter on the sqldatasource of the related griddropdownbox??
I guess there is no way to utilize a controlparameter or sessionparameter tied back to the selected id of the controlling griddropdownbox?
answered on 30 Aug 2012, 07:49 AM
This functionality cannot be achieved declaratively. Even if you manage to use a control or session parameter with the SqlDataSource for the RadComboBoxes, the combos are bound at the same time, meaning that this parameter would still be empty for the second combo when it is databound. So, you would need to perform logic on SelectedIndexChanged of the first combo to populate the second one with a filtered datasource.
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