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This article introduces the relevant knowledge of "C# support event example Analysis". In the operation of actual cases, many people will encounter such a dilemma. Then let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Here we introduce that C# supports events (which is also a feature of MSVJ). At present, many mainstream programming languages handle events in different ways. Delphi uses function pointers (which is the term "closure" in Delphi), Java uses adapted classes to implement, VC uses WindowsAPI's messaging system, and C# uses delegate and event keywords directly to solve this problem. Let's take a look at an example that gives you the whole process of declaring, invoking, and handling events.

/ / first is the declaration of reference, which defines the event signal public delegate void ScoreChangeEventHandler (int newScore, ref bool cancel) that wakes up a function; / / defines a class public class Game that generates events {/ / Note that the event keyword public event ScoreChangeEventHandler ScoreChange; int score; / / Score attribute public int Score {get {return score;} set {if (score! = value) {bool cancel = false is used here. ScoreChange (value, ref cancel); if (! Cancel) score = value;} / / the event handling class public class Referee {public Referee (Game game) {/ / the referee is responsible for adjusting the score changes in the game game.ScoreChange + = new ScoreChangeEventHandler (game_ScoreChange);} / / notice how the function here corresponds to the private void game_ScoreChange (int newScore, ref bool cancel) {if (newScore < 100) System.Console.WriteLine ("Good Score") of the ScoreChangeEventHandler signal. Else {cancel = true; System.Console.WriteLine ("No Score can be that high!");} / / main function class, used to test the above features public class GameTest {public static void Main () {Game game = new Game (); Referee referee = new Referee (game); game.Score = 70; game.Score = 110;}}

In the main function, we create a game object and a referee object, and then we change the game score to see how the referee responds to this.

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