Dynamically create Gridview with Dropdowns

Question

hi Every one 
I need to generate GV Dynamically and that contains Dropdowns  for every column and That Dropdowns should be filled with respective secleted indexed event.So How can I implement secleted indexed event for All Dropdowns.the columns may be 1....n so dropdownd also 1...n how can i do this .please give me any Idea......