Expressing Designs in C# - Effective C# - page 149

public void AddMsg( int priority, string msg)
{
EventHandler < LoggerEventArgs > l = log;
if (l != null )
l( null , new LoggerEventArgs (priority, msg));
}
}
The C# compiler creates the add and remove accessors for the event. I find
the public event declaration language more concise and easier to read and
maintain than the add/remove syntax. When you create events in your
class, declare public events and let the compiler create the add and remove
properties for you. Writing your own add and remove handlers lets you do
more work in the add and remove handlers.
Events do not need to have any knowledge about the potential listeners.
The following class automatically routes all messages to the Standard Error
console:
class ConsoleLogger
{
static ConsoleLogger()
{
Logger .Singleton.Log += (sender, msg) =>
{
Console .Error.WriteLine( "{0}:\t{1}" ,
msg.Priority.ToString(),
msg.Message);
};
}
}
Another class could direct output to the system event log:
class EventLogger
{
private static Logger logger = Logger .Singleton;
private static string eventSource;
private static EventLog logDest;
static EventLogger()
{