Delegate event handlers (i.e. delegates used as type of an event) should have a very specific signature:
- Return type
void.
- First argument of type
System.Object and named 'sender'.
- Second argument of type
System.EventArgs (or any derived type) and is named 'e'.
This rule raises an issue whenever a delegate declaration doesn’t match that signature.
Noncompliant code example
public delegate void AlarmEventHandler(object s);
public class Foo
{
public event AlarmEventHandler AlarmEvent; // Noncompliant
}
Compliant solution
public delegate void AlarmEventHandler(object sender, AlarmEventArgs e);
public class Foo
{
public event AlarmEventHandler AlarmEvent; // Compliant
}
