1 using System;
2
3 namespace ConsoleApp3_Test
4 {
5
6 internal class Aa
7 {
8
9 static void Main(string[] args)
10 {
11 Stock stock = new Stock("THPW");
12 stock.Price = 27.10M;
13
14 //Register with the PriceChanged event
15 stock.PriceChanged += stock_PriceChanged;
16 stock.Price = 31.59M;
17 }
18
19 static void stock_PriceChanged(object sender, PriceChangedEventArgs e)
20 {
21 Console.WriteLine($"LastPrice:{e.LastPrice}\t\tNewPrice:{e.NewPrice}");
22
23 if (e.LastPrice != 0 && (e.NewPrice - e.LastPrice) / e.LastPrice > 0.1M)
24 Console.WriteLine("Alert, 10% stock price increase!");
25
26 Console.WriteLine();
27 }
28 }
29
30 public class PriceChangedEventArgs : EventArgs
31 {
32 public readonly decimal LastPrice;
33 public readonly decimal NewPrice;
34
35 public PriceChangedEventArgs(decimal lastPrice, decimal newPrice)
36 {
37 LastPrice = lastPrice;
38 NewPrice = newPrice;
39 }
40 }
41
42 public class Stock
43 {
44 string symbol;
45 decimal price;
46 public Stock(string symbol) { this.symbol = symbol; }
47
48 public event EventHandler<PriceChangedEventArgs> PriceChanged;
49
50 protected virtual void OnPriceChanged(PriceChangedEventArgs e)
51 {
52 PriceChanged?.Invoke(this, e);
53 }
54
55 public decimal Price
56 {
57 get { return price; }
58 set
59 {
60 if (price == value) return;
61 decimal oldPrice = price;
62 price = value;
63 OnPriceChanged(new PriceChangedEventArgs(oldPrice, price));
64 }
65 }
66 }
67 }
