Raise an event from a DLL to an application

[geezerjoe]

I have a C# solution with 2 projects, a test form in one project and a DLL in another. The DLL connects to a socket and sends and receives messages to and from the test application using properties in the DLL.
How does one send an event, such as poll events of the socket, to the test application? I want to know if the connection was dropped, when it was dropped, and set a button to red when connection is lost.
Very new to C# and I hope I framed the question well enough to get an answer.
Thanks in advance,
Joe

[Plater]

Create an event in your DLL, have it "fire" when the Poll events show that the socket is disconnected (bravo for knowing that Poll() can be used to detect an instant disconnect)
Then have your main program attach an event listener for it.

[geezerjoe]

Create an event in your DLL, have it "fire" when the Poll events show that the socket is disconnected (bravo for knowing that Poll() can be used to detect an instant disconnect)
Then have your main program attach an event listener for it.

Thank you!
Will I have to poll/raise event in a seperate thread? Is threading even a concern here?
Thank you again, Joe

[Plater]

If you are already doing the Poll() calls in your DLL, all you need do is fire that event if it ever fails.