What is the use of "object sender" and "EventArgs e" parameters?

c# asp.net events sender eventargs
Qasim picture Qasim · Jan 23, 2013 · Viewed 185k times · Source

In case of Page_Load, Init and other page events, what is the use of these (object sender, EventArgs e) parameters?

Examples would be more helpful.

Answer

Vinayak Pahalwan picture Vinayak Pahalwan · Jan 23, 2013

EventArgs e is a parameter called e that contains the event data, see the EventArgs MSDN page for more information.

Object Sender is a parameter called Sender that contains a reference to the control/object that raised the event.

Event Arg Class: http://msdn.microsoft.com/en-us/library/system.eventargs.aspx

Example:

protected void btn_Click (object sender, EventArgs e){
   Button btn = sender as Button;
   btn.Text = "clicked!";
}

Edit: When Button is clicked, the btn_Click event handler will be fired. The "object sender" portion will be a reference to the button which was clicked

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