Inside asp.net form I have few dynamically generated buttons, all of this buttons submit a form, is there a way to get which button was submit the form in page load event?
This won't work if your code is inside a user control:
Request.Form.AllKeys.Contains("btnSave") ...
Instead you can try this:
if (Request.Form.AllKeys.Where(p => p.Contains("btnSave")).Count() > 0) { // btnSave was clicked, your logic here }