Delegates, What are they?

Hi Eduardo,

Delegates: - It is a procedure pointer, which stores the memory address of another procedure.

Ex:-

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public delegate void abhisek(int x, int y);

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            abhisek a = null;
            a = rajiv;
            a.Invoke(10, 20);

        }
        public void rajiv(int x, int y)
        {
            int z = 0;
            z = x + y;
            MessageBox.Show(z.ToString());
        }

    }
}



Thanks

Thank you for your time. This is very interesting. So, the delagate would be a kind of "middle man" between the two methods you are talking about ... is this correct?

So, in the example you are giving me, Couldn't I just use a method with if-else or a switch statement to identify the iformation coming from the port to let's say a  GetScannerInformation() for example?

Thanks you,

 

Eduardo

probably the most basic use of Delegates is for updating a form using a "background" process.

so that you have a serial port open waiting for a barcode scanner to scan something.  when something is scanned, it will fire the "receiveData" event for the serial port.  however, you would not be able to update the form with the data from the scan because they were started in different threads.  so you would use a delegate.  the delegate would "delegate" between the main thread and another thread allowing you to set .Text properties on the form.

that's my interpretation from using them.