Object Sender and EventArgs

Question

Consider this function signature:

Private Void TextBox1_TextChange(Object Sender, EventArgs e)

As far as my knowledge goes I understand it as below.

1. Private is a modifier

2. Void is the return type

3. TextBox1_TextChange is an event name.

Maybe I am wrong in the above case as I just started practicing in C#, Visual Studio 2005.

What is the definition/meaning of (Object Sender, EventArgs e) and how does it work?

Answer 1

TextChange is (probably) the name of the relevant event, though the event isn't shown in your code snippet so I can't be sure.

TextBox1_TextChange is the name of a method that is probably set up to handle an event.

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

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

See this page, Passing Parameters , for more information about how parameters work.

And this page, Events Tutorial , would probably be helpful as well.

Answer 2

Object Sender: which object is invoked the current event.in your case TextBox1 is sender. EventArgs e :e is the object for EventArgs, when TextChange is invoked object e contain arguments.