GridView - A simple implementation of cascading comboboxes in Batch Edit mode

In this example, the combo box in the City column (the City combo box) is populated dynamically with city names via callbacks, based on the value selected in the combo box in the Country column (the Country combo box). 
You can find detailed steps by clicking below the "Show Implementation Details" link .

Web Forms: 
ASPxGridView - How to implement cascading comboboxes in Batch Edit mode