Writing this mostly for when I need a quick snippet, but in
case someone finds this useful.
The C# delegate beast is an object which holds references to methods (think “object-like method” that can be strong typed and therefore checked, unlike C++ function pointers), so this makes them super useful to pass as method parameters or to run a bunch of methods in event callbacks. This particular example uses Reactive Extensions so you will need to install them with Nuget.
The C# delegate beast is an object which holds references to methods (think “object-like method” that can be strong typed and therefore checked, unlike C++ function pointers), so this makes them super useful to pass as method parameters or to run a bunch of methods in event callbacks. This particular example uses Reactive Extensions so you will need to install them with Nuget.
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Reactive; using System.Reactive.Disposables; using System.Reactive.Subjects; namespace DelegateTest { // Delegate definition. public delegate void ProcessDelegate(); public class Processor { // Reactive observable. public Subject<Task> Observable = new Subject<Task>(); // Task to process. public void Process(Task Process) { Process.Start(); } // Delegate instance. public ProcessDelegate ProcessInstance; // Constructor. public Processor(IEnumerable<ProcessDelegate> Processes, ProcessDelegate ProcessCompleted) { // Initialise delegate instance. // Add process methods. foreach (var Process in Processes) ProcessInstance += Process; // Add process completed method. ProcessInstance += ProcessCompleted; } } public class Program { static void Main(string[] args) { Console.WriteLine("Starting process test ..."); // Create test process object. Processor Test = new Processor( // Delegate implementations. new List<ProcessDelegate> { () => { string Result = ""; for(int Index = 0; Index < 100; Index++) Result += Index.ToString(); Console.WriteLine("Process 1 finished = " + Result.Substring(0, 10) + " ... "); }, () => { string Result = ""; for(int Index = 0; Index < 100; Index++) Result += Index.ToString(); Console.WriteLine("Process 2 finished = " + Result.Substring(0, 10) + " ... "); }, () => { string Result = ""; for(int Index = 0; Index < 100; Index++) Result += Index.ToString(); Console.WriteLine("Process 3 finished = " + Result.Substring(0, 10) + " ... "); } }, () => { Console.WriteLine("Processes completed ... "); } ); // Assign processes/delegate to an observable task. Test.Observable.Subscribe( Value => Test.Process( Value ), () => { Console.WriteLine("Observable OnCompleted called ... "); } ); // Run action on the observable. // Assigning delegate implementations. Test.Observable.OnNext( new Task(new Action(Test.ProcessInstance))); Console.WriteLine("Carrying on with some other tasks ..."); Console.ReadLine(); } } }
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