You're accessing so many items without null checks that it could be any number of things. Are you sure all of the controls exist in the cells you're specifying?
The secret lies in the event handlers–in this case, the Row Updating event handler. Grid View Update Event Args object that is passed in. This page contains copyright material from you have no rights to copy and paste the full text into your own blog even if you have written permission to the contrary.
Using the Row Updating handler, we can do whatever we want. What the line of code says is “cancel any other update processing that may have happened after this event gets called.” From here on out, you’ll need to retrieve the values from your edit controls manually using the Find Contro By ID() method I demonstrated on Monday and updating the database using code. – For a while now I’m trying to figure out why my method, triggered by the Grid View.
I removed everything I did with View State and edited the original post again with what I currently got. I cannot sort the Grid View because I'm trying to sort with Your code doesn't have Data Source ID.
When I Filter the data using dropdown selected Index Changed event the gridview shall load data based on what is searched.
Simple Insert, Select, Edit, Update and Delete in Asp. – The above block of codes in Row Updating event, finds the control in the Grid View, takes those values in pass it to the Customers Cls class Update method.