From PluralSight C# Events, Delegates and Lambdas
Module 1 - Events, Delegates, and Event Handlers
Events - A notification that goes to a subscriber (Button_Click)
Mouse press triggers a click event. Multiple objects can listen to an event by subscribing Events pass EventArgs (event data) Button has x-pos, y-pos
Delegates - pipeline between event and event handler Specialized class that is called a "Function Pointer" Delegates take data from Event to EventHandler (Function/Method)
EventHandler - method that receives and processes data from delegaete Normally, two Parameters (object sender, EventArgs e)
Module 2 - Creating Delegates public delegate void WorkPerformedHandler(int hours, WorkType workType);
A delegate is the blueprint for a method (method pointer) where data is going to get dumped into. A delegate takes data to a method handler.
The delegate signature must be matched by the Handler method. public void Manager_WorkPerformed(int workHours, WorkType wType) { Console.WriteLine("WorkPerformed1 called"); }
To hook up the Handler, new the delegate and pass the method name WorkPerformedHandler del1 = new WorkPerformedHandler(Manager_WorkPerformed);
Invoke the delgate del1(5, WorkType.Golf);
Module 3 - Lambdas Lambdas are just a way of writing delgate code so it is cleaner and simpler. Also, you can build expression trees.
Lambdas just define the 'parameters' and the 'anonymous' code block. It is just the definition of the code.