Is the Template Field necessary to get the new values during Item Updating event? In order to take off any doubts below is my for your suggestion. But when i set up a breakpoint and read changed Text Box value, it is still the old value( the value before Edit button is pressed). In other words it is not reading Newly entered value during Edit/Update process. New Values is a collection that holds the new values that were entered. You use it to change or update any values, prior to the data being written back to the data store.
Regarding on the accesing Bound Field nested controls in Details View control, since it is autogenerated by runtime and will assign a random id according to the item index, we can not use Find Control method to locate the nested control instance When Bound Fields or Template Field used in Details View control during the Edit and Item Updating event either Bound Field columns new Text or Template Field new Text can not be accessed. Either of them are not returning new values i m afraid.
Refer here: View (and Grid View) don't work properly when not used with a proper datasource. :) you did but what I meant was that you were using this: //Even this Find Control does not help either to read the newly entered Text // Text Box test = (Text Box) dv User Record.