C# Custom Events Example

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 Custom_Events_Test
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        Person p1 = new Person();
        Person p2 = new Person();

        private void Form1_Load(object sender, EventArgs e)
        {
            CreateEvents();
            p1.Name = "Jesse";
            p2.Name = "Brian";
            txtName1.Text = p1.Name;
            txtName2.Text = p2.Name;
        }

        private void CreateEvents()
        {
            p1.OnCashChanged += new Person.CashEventHandler(person_OnCashChanged);
            p1.OnCashAdded += new Person.CashEventHandler(person_OnCashAdded);
            p1.OnCashRemoved += new Person.CashEventHandler(person_OnCashRemoved);
            p2.OnCashChanged += new Person.CashEventHandler(person_OnCashChanged);
            p2.OnCashAdded += new Person.CashEventHandler(person_OnCashAdded);
            p2.OnCashRemoved += new Person.CashEventHandler(person_OnCashRemoved);
        }

        void person_OnCashRemoved(Person x)
        {
            txtLogs.Text += x.Name + " spent Money!" + "\r\n";
        }

        void person_OnCashAdded(Person x)
        {
            txtLogs.Text += x.Name+" got "+x.GetCash()+" cash!" + "\r\n";
        }

        void person_OnCashChanged(Person x)
        {
            lblCash.Text = x.GetCash().ToString() + "$";
            lblCash2.Text = x.GetCash().ToString() + "$";
            //txtLogs.Text += x.Name+"'s Cash has been changed!" +"\r\n";
        }

        private void buttonExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void buttonAddCash_Click(object sender, EventArgs e)
        {
            p1.AddCash(p1, double.Parse(txtAddCash.Text));
        }

        private void buttonSetCash_Click(object sender, EventArgs e)
        {
            p1.SetCash(p1, double.Parse(txtAddCash.Text));
        }

        private void buttonRemoveCash_Click(object sender, EventArgs e)
        {
            p1.RemoveCash(p1, double.Parse(txtRemoveCash.Text));
        }

        private void button1_Click(object sender, EventArgs e)
        {
            MessageBox.Show("" + p1.Name + " has " + p1.GetCash().ToString() + "$");
        }

        private void buttonAddCash2_Click(object sender, EventArgs e)
        {
            p2.AddCash(p2, double.Parse(txt1.Text));
        }

        private void buttonSetCash2_Click(object sender, EventArgs e)
        {
            p2.SetCash(p2, double.Parse(txt2.Text));
        }

        private void buttonRemoveCash2_Click(object sender, EventArgs e)
        {
            p2.RemoveCash(p2, double.Parse(txt3.Text));
        }
    }

    class Person
    {
        public delegate void CashEventHandler(Person x);

        public event CashEventHandler OnCashChanged;
        public event CashEventHandler OnCashAdded;
        public event CashEventHandler OnCashRemoved;

        private double _Cash;
        private string _Name;

        public string Name
        {
            get { return _Name; }
            set { _Name = value; }
        }

        public void SetCash(Person p, double Amount)
        {
            if (Amount != _Cash && OnCashChanged != null) OnCashChanged(p);
            this._Cash = Amount;
        }

        public void AddCash(Person p, double Amount)
        {
            this._Cash += Amount;
            if (OnCashChanged != null) OnCashChanged(p);
            if (OnCashAdded != null) OnCashAdded(p);
        }

        public void RemoveCash(Person p, double Amount)
        {
            if (Amount <= 0) return;
            this._Cash -= Amount;
            if (OnCashChanged != null) OnCashChanged(p);
            if (OnCashRemoved != null) OnCashRemoved(p);
        }

        public double GetCash()
        {
            return this._Cash;
        }
    }
}