c# - How does addition assignment operator behave -

how addition assignment operator behaves here -

btn.click += delegate(object sender, eventargs e) 

it adds event handler event click. when click event raised handlers method added called.

for example:

void btnclickhandler1(object sender, eventargs e) {     messagebox.show("btnclickhandler1"); }  void btnclickhandler2(object sender, eventargs e) {     messagebox.show("btnclickhandler2"); } 

and add these methods click event this:

btn.click += btnclickhandler1 btn.click += btnclickhandler2 

when button clicked methods called in order added them, message box be:

btnclickhandler1 btnclickhandler2 

if want specific info += operator, msdn says:

the += operator used specify method called in response event; such methods called event handlers. use of += operator in context referred subscribing event.

for more info at:

https://msdn.microsoft.com/en-us/library/edzehd2t%28v=vs.110%29.aspx

http://www.dotnetperls.com/event