A small example of a delegate-based C # asynchronous programming with a callback function example

I created a WinForm test project: The interface is as follows:

Set up:

Here's the code:

usingSystem;usingSystem.Collections.Generic;usingSystem.ComponentModel;usingSystem.Data;usingSystem.Drawing;usingSystem.Linq;usingSystem.Text;usingSystem.Threading;usingSystem.Threading.Tasks;usingSystem.Windows.Forms;namespaceasynccallbackdemo{ Public Partial classForm1:form { PublicForm1 () {InitializeComponent (); Objmycal=ExecuteTask; }        //define a delegate         Public Delegate intMycalculator (intNumintms); //based on the delegate definition method, returns the square of a number        Private intExecuteTask (intNumintms)            {Thread.Sleep (MS); returnNum *num; } mycalculator objmycal=NULL; Private voidButton1_Click (Objectsender, EventArgs e) {                      for(inti =0; I < One; i++)            {                //defining the callback function Mycallback, passing in the callback value IObjmycal.begininvoke (TenI +*1, Mycallback, i); }        }        Private voidmycallback (IAsyncResult result) {//return Results            intres =Objmycal.endinvoke (Result); Console.WriteLine ("{ 0} evaluates to {1}", result.        Asyncstate.tostring (), res); }           }}

A small example of a delegate-based C # asynchronous programming with an example of a callback function