public void DemoNotification(string s, DelegateForNotification outputFunction)
{
Console.WriteLine("we're going to process the string:");
if (outputFunction != null)
{
Console.WriteLine("Function that is used as delegate is: {0}", s);
Console.WriteLine("Delegate output is: {0}", outputFunction);
}
else
Console.WriteLine("We are sorry, but no processing methods were registered!!!");
}
static void Main(string[] args)
{
Console.WriteLine("------------------Delegates----------------");
Notificator notificator = new Notificator();
NotificationHandler notificationHandler = new NotificationHandler();
// calling static delegates
notificator.DemoNotification("static example", null); // nothing will happen here since we don't pass the parameter
notificator.DemoNotification("static example", new
DelegateForNotification(NotificationHandler.SendNotificationByInstantMessenger)); // nothing happening here
notificator.DemoNotification("instance example", null);//nothing happen here we don't pass any handler
notificator.DemoNotification("instance example", new DelegateForNotification(notificationHandler.SendNotificationByMail));
notificator.DemoNotification("instance example", new DelegateForNotification(notificationHandler.SendNotificationByFax));
NotificationHandler nullhandler = null;
try
{
notificator.DemoNotification("instance example", new DelegateForNotification(nullhandler.SendNotificationByFax));
}
catch (System.ArgumentException e)
{
Console.WriteLine("We've tried to pass null object for delegate and catched: " + e.Message);
}
//------------------DELEGATES CHAIN-----------
Console.WriteLine("-----------------------------DELEGATES CHAIN--------------------:");
DelegateForNotification dlg1 = new DelegateForNotification(NotificationHandler.SendNotificationByInstantMessenger);
DelegateForNotification dlg2 = new DelegateForNotification(notificationHandler.SendNotificationByMail);
DelegateForNotification dlg3 = new DelegateForNotification(notificationHandler.SendNotificationByFax);
DelegateForNotification dlg_chain = null;
dlg_chain += dlg1;
dlg_chain += dlg2;
dlg_chain = (DelegateForNotification)Delegate.Combine(dlg_chain, dlg3);//more complex way to combine delegate to chain
//you can view invocation list
Delegate[] list = dlg_chain.GetInvocationList();
foreach (Delegate del in list)
{
Console.WriteLine("Method: " + del.Method.ToString());
}
notificator.DemoNotification("chain example", dlg_chain);//calling notification to chain from 3 functions
Console.ReadKey();
}
