. NET non-blocking event get returns asynchronous callback result

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading;namespaceasynccallback_delegate{classProgram {Static voidMain (string[] args) {JobManager Manager=NewJobManager (); Readjob Read= Manager. Run<readjob>(); Read. Started+=NewEventHandler (read_started); Read.completed+=NewEventhandler<completedeventargs>(read_completed); Read. OnUnhandledException+=NewEventhandler<exceptioneventargs>(read_onunhandledexception); Read.            Execute ();  while(!read. iscompleted) {Console.WriteLine ("Main thread["+ Thread.CurrentThread.ManagedThreadId +"] is waiting to close ..."); Thread.Sleep ( -); } Console.WriteLine ("Readjob is completed and return value:"+read.            RetVal); Console.WriteLine ("Jobs has been finished, press any key to continue ...");        Console.readkey (); }        Static voidRead_onunhandledexception (Objectsender, Exceptioneventargs e) {Console.WriteLine ("Exception:"+ Sender. GetType (). FullName +"Exception Message:"+e.message); }        Static voidRead_completed (Objectsender, CompletedEventArgs e) {Console.WriteLine ("Completed:"+ Sender. GetType (). FullName +"Process executed Result:"+e.success); }        Static voidRead_started (Objectsender, EventArgs e) {Console.WriteLine ("Started:"+sender. GetType ().        FullName); }    }     Public classJobManager { PublicT run<t> ()whereT:ijobservice,New()        {            return NewT (); }    }     Public InterfaceIjobservice {voidExecute (); EventEventhandler<completedeventargs>completed; EventEventHandler Started; EventEventhandler<exceptioneventargs>onunhandledexception; }    Delegate voidProcessdelegate (stringmessage);  Public classReadjob:ijobservice {//Define events for Readjob instance objects to register externally         Public EventEventHandler Started;  Public EventEventhandler<completedeventargs>completed;  Public EventEventhandler<exceptioneventargs>onunhandledexception; ObjectLockobj =New Object(); EventEventhandler<completedeventargs>ijobservice.completed {add {Lock(lockobj) {completed+=value; }} remove {Lock(lockobj) {completed-=value; }            }        }        EventEventHandler ijobservice.started {add {Lock(lockobj) {Started+=value; }} remove {Lock(lockobj) {Started-=value; }            }        }        EventEventhandler<exceptioneventargs>Ijobservice.onunhandledexception {add {Lock(lockobj) {onunhandledexception+=value; }} remove {Lock(lockobj) {onunhandledexception-=value; }            }        }         Public BOOLiscompleted {Get;Set; }  Public BOOLRetVal {Get;Set; }  Public voidExecute () {iscompleted=false; RetVal=false; EventHandler EventHandler=Started; if(NULL!=EventHandler) {EventHandler ( This,NewEventArgs ()); }            //calling the Process method in asynchronous callback mode//The return value and the completed event are called in the callback methodProcessdelegate process =Process; Process. BeginInvoke ("Readjob", Completedmethod, process); }         Public voidProcess (String message) {Console.WriteLine ("Process thread["+ Thread.CurrentThread.ManagedThreadId +"]:"+ Message +"Jobservice:"+ This. GetType ().            FullName); Thread.Sleep ( -); //Test//throw new Exception ("Test Exception");        }        //method called after completion of asynchronous callback execution         Public voidCompletedmethod (IAsyncResult result) {//Get return value            Try{(result. AsyncState asprocessdelegate).                EndInvoke (result); RetVal=true; //thread synchronization uses temporary variables instead of EventHandler, and delegates are immutable immutable//You can also use Interlocked.compareexchange (ref eventhandler,null,null)Eventhandler<completedeventargs> EventHandler =completed; if(NULL!=EventHandler) {EventHandler ( This,NewCompletedEventArgs (true)); }            }            Catch(Exception ex) {//exception-handling events are executed again, thread synchronization uses temporary variables instead of EventHandler, and delegates are immutable immutable//You can also use Interlocked.compareexchange (ref eventhandler,null,null)eventhandler<exceptioneventargs> eh =onunhandledexception; if(NULL!=eh) {EH ( This,NewExceptioneventargs (ex.                Message)); } RetVal=false; }            //executes the completed event registration method, where the EventHandler temporary variable is used to avoid the event being removed if NULL is judged//If you need to use multithreadingIsCompleted =true; }    }     Public classCompletedeventargs:eventargs { Public BOOLSuccess {Get;Set; }  PublicCompletedEventArgs (BOOLsuccess) {             This. Success =success; }    }     Public classExceptioneventargs:eventargs { Public stringMessage {Get;Set; }  PublicExceptioneventargs (stringmessage) {             This. Message =message; }    }}

. NET non-blocking event get returns asynchronous callback result