Delegates and events

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading.Tasks;namespacedelegateandevent{ Public  classCaculator {//Dim a caculateeventargs,used to save the status info when call the event         Public classCaculateeventargs:eventargs { Public ReadOnly intx, y;  PublicCaculateeventargs (intXinty) { This. x =x;  This. y =y; }        }        //Dim the event delegate         Public Delegate voidCalculateeventhandler (ObjectSender,caculateeventargs e); //Dim the Event         Public EventCalculateeventhandler mycalculate; //Support the virtual function//provides a protected virtual method that can be overridden by subclasses to deny monitoring        protected Virtual voidOnCalculate (Caculateeventargs e) {if(mycalculate!=NULL) {mycalculate ( This, E); }        }        //to make a calculation, call the release to indicate that a new calculation has occurred         Public voidCalculate (intXinty) {Caculateeventargs e=NewCaculateeventargs (x, y); //Notify all event registrantsOnCalculate (e); }    }}

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading.Tasks;namespacedelegateandevent{/// <summary>    ///Dingyuan Event Trigger/// </summary>    Public  classCaculatormanager { Public voidADD (ObjectSender,caculator.caculateeventargs e) {Console.WriteLine (e.x+e.y); }        Public voidSubstract (ObjectSender,caculator.caculateeventargs e) {Console.WriteLine (e.x-e.y); }    }}

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading.Tasks;namespacedelegateandevent{classProgram {Static voidMain (string[] args) {Caculator Calculator=Newcaculator (); //Event TriggerCaculatormanager cm =NewCaculatormanager (); //Event BindingsCalculator. Mycalculate + =cm.            ADD; Calculator. Calculate ( -, $); Calculator. Mycalculate+=cm.            Substract; Calculator. Calculate ( -, $); //Event LogoffCalculator. Mycalculate-=cm.            ADD; Calculator. Calculate ( -, $);        Console.read (); }    }}

Output:

300

300

-100

-100

Delegates and events