利用SignalR实施响应股票数据波动

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1.新建ASP.NET Web应用程序, 选择Empty模板。

2.创建Stock.cs类

 1  public class Stock
 2     {
 3         /// <summary>
 4         /// 价格
 5         /// </summary>
 6         private decimal _price;
 7 
 8         /// <summary>
 9         /// 象征
10         /// </summary>
11         public string Symbol { get; set; }
12 
13         public decimal Price
14         {
15             get
16             {
17                 return _price;
18             }
19             set
20             {
21                 if (_price == value)
22                 {
23                     return;
24                 }
25 
26                 _price = value;
27 
28                 if (DayOpen == 0)
29                 {
30                     DayOpen = _price;
31                 }
32             }
33         }
34         /// <summary>
35         /// 开放
36         /// </summary>
37         public decimal DayOpen { get; private set; }
38 
39        /// <summary>
40        /// 变动
41        /// </summary>
42         public decimal Change
43         {
44             get
45             {
46                 return Price - DayOpen;
47             }
48         }
49 
50         /// <summary>
51         /// 变动百分比
52         /// </summary>
53         public double PercentChange
54         {
55             get
56             {
57                 return (double)Math.Round(Change / Price, 4);
58             }
59         }
60     }

Stock.cs

3.选择程序包管理控制台，添加SignalR Nuget包

输入命令 install-package Microsoft.AspNet.SignalR

4.选择添加SignalR Hub Class（v2），命名StockTickerHub

5.StockTickerHub.cs类

 1  [HubName("stockTickerMini")]
 2     public class StockTickerHub : Hub
 3     {
 4    private readonly StockTicker _stockTicker;
 5 
 6         public StockTickerHub() : this(StockTicker.Instance) { }
 7 
 8         public StockTickerHub(StockTicker stockTicker)
 9         {
10             _stockTicker = stockTicker;
11         }
12 
13         public IEnumerable<Stock> GetAllStocks()
14         {
15             return _stockTicker.GetAllStocks();
16         }
17     }

StockTickerHub.cs

6.添加StockTicker.cs类

 1   public class StockTicker
 2     {
 3         // 单例线程
 4         private readonly static Lazy<StockTicker> _instance = new Lazy<StockTicker>(() => new StockTicker(GlobalHost.ConnectionManager.GetHubContext<StockTickerHub>().Clients));
 5         private readonly ConcurrentDictionary<string, Stock> _stocks = new ConcurrentDictionary<string, Stock>();
 6         private readonly object _updateStockPricesLock = new object();
 7         private readonly double _rangePercent = .002;
 8         private readonly TimeSpan _updateInterval = TimeSpan.FromMilliseconds(250);
 9         private readonly Random _updateOrNotRandom = new Random();
10         private readonly Timer _timer;
11         //_updatingStockPrices标志被标记为volatile以确保对其进行线程安全访问。
12         private volatile bool _updatingStockPrices = false;
13 
14         private StockTicker(IHubConnectionContext<dynamic> clients)
15         {
16 
17             //构造函数使用一些示例股票数据初始化_stocks集合，
18             //GetAllStocks返回股票。
19             //这些股票集合又由StockTickerHub.GetAllStocks返回，
20             //这是客户可以调用的Hub类中的服务器方法。
21             Clients = clients;
22             _stocks.Clear();
23             var stocks = new List<Stock>
24             {
25                 new Stock { Symbol = "MSFT", Price = 30.31m },
26                 new Stock { Symbol = "APPL", Price = 578.18m },
27                 new Stock { Symbol = "GOOG", Price = 570.30m }
28             };
29             stocks.ForEach(stock => _stocks.TryAdd(stock.Symbol, stock));
30 
31             //构造函数启动一个Timer对象，
32             //该对象定期调用随机更新股票价格的方法。
33             _timer = new Timer(UpdateStockPrices, null, _updateInterval, _updateInterval);
34 
35         }
36 
37         public static StockTicker Instance
38         {
39             get
40             {
41                 return _instance.Value;
42             }
43         }
44 
45         private IHubConnectionContext<dynamic> Clients
46         {
47             get;
48             set;
49         }
50 
51         public IEnumerable<Stock> GetAllStocks()
52         {
53             return _stocks.Values;
54         }
55         private void UpdateStockPrices(object state)
56         {
57             lock (_updateStockPricesLock)
58             {
59                 if (!_updatingStockPrices)
60                 {
61                     _updatingStockPrices = true;
62 
63                     foreach (var stock in _stocks.Values)
64                     {
65                         if (TryUpdateStockPrice(stock))
66                         {
67                             BroadcastStockPrice(stock);
68                         }
69                     }
70 
71                     _updatingStockPrices = false;
72                 }
73             }
74         }
75         private bool TryUpdateStockPrice(Stock stock)
76         {
77             // Randomly choose whether to update this stock or not
78             var r = _updateOrNotRandom.NextDouble();
79             if (r > .1)
80             {
81                 return false;
82             }
83 
84             // Update the stock price by a random factor of the range percent
85             var random = new Random((int)Math.Floor(stock.Price));
86             var percentChange = random.NextDouble() * _rangePercent;
87             var pos = random.NextDouble() > .51;
88             var change = Math.Round(stock.Price * (decimal)percentChange, 2);
89             change = pos ? change : -change;
90 
91             stock.Price += change;
92             return true;
93         }
94 
95         private void BroadcastStockPrice(Stock stock)
96         {
97             Clients.All.updateStockPrice(stock);
98         }
99     }

StockTicker.cs

7.添加Startup.cs类

1  public class Startup
2     {
3         public void Configuration(IAppBuilder app)
4         {
5             app.MapSignalR();
6         }
7     }

Startup.cs

8.设置前端代码

 1 <!DOCTYPE html>
 2 <html xmlns="http://www.w3.org/1999/xhtml">
 3 <head>
 4     <title>ASP.NET SignalR Stock Ticker</title>
 5     <style>
 6         body {
 7             font-family: 'Segoe UI', Arial, Helvetica, sans-serif;
 8             font-size: 16px;
 9         }
10 
11         #stockTable table {
12             border-collapse: collapse;
13         }
14 
15             #stockTable table th, #stockTable table td {
16                 padding: 2px 6px;
17             }
18 
19             #stockTable table td {
20                 text-align: right;
21             }
22 
23         #stockTable .loading td {
24             text-align: left;
25         }
26 
27         #stockTicker {
28             overflow: hidden;
29             width: 450px;
30             height: 24px;
31             border: 1px solid #999;
32         }
33 
34             #stockTicker .inner {
35                 width: 9999px;
36             }
37 
38             #stockTicker ul {
39                 display: inline-block;
40                 list-style-type: none;
41                 margin: 0;
42                 padding: 0;
43             }
44 
45             #stockTicker li {
46                 display: inline-block;
47                 margin-right: 8px;
48             }
49 
50             /*<li data-symbol="{Symbol}"><span class="symbol">{Symbol}</span><span class="price">{Price}</span><span class="change">{PercentChange}</span></li>*/
51             #stockTicker .symbol {
52                 font-weight: bold;
53             }
54 
55             #stockTicker .change {
56                 font-style: italic;
57             }
58     </style>
59 </head>
60 <body>
61     <h1>ASP.NET SignalR Stock Ticker Sample</h1>
62 
63     <h2>Live Stock Table</h2>
64     <div id="stockTable">
65         <table border="1">
66             <thead>
67                 <tr><th>Symbol</th><th>Price</th><th>Open</th><th>Change</th><th>%</th></tr>
68             </thead>
69             <tbody>
70                 <tr class="loading"><td colspan="5">loading...</td></tr>
71             </tbody>
72         </table>
73     </div>
74 
75     <!--Script references. -->
76     <!--Reference the jQuery library. -->
77     <script src="/Scripts/jquery-1.10.2.min.js"></script>
78     <!--Reference the SignalR library. -->
79     <script src="/Scripts/jquery.signalR-2.1.2.js"></script>
80     <!--Reference the autogenerated SignalR hub script. -->
81     <script src="/signalr/hubs"></script>
82     <!--Reference the StockTicker script. -->
83     <script src="StockTicker.js"></script>
84 </body>
85 </html>

html

9.创建StockTicker.js

 1 // A simple templating method for replacing placeholders enclosed in curly braces.
 2 if (!String.prototype.supplant) {
 3     String.prototype.supplant = function (o) {
 4         return this.replace(/{([^{}]*)}/g,
 5             function (a, b) {
 6                 var r = o[b];
 7                 return typeof r === 'string' || typeof r === 'number' ? r : a;
 8             }
 9         );
10     };
11 }
12 
13 $(function () {
14 
15     var ticker = $.connection.stockTickerMini, // the generated client-side hub proxy
16         up = '▲',
17         down = '▼',
18         $stockTable = $('#stockTable'),
19         $stockTableBody = $stockTable.find('tbody'),
20         rowTemplate = '<tr data-symbol="{Symbol}"><td>{Symbol}</td><td>{Price}</td><td>{DayOpen}</td><td>{Direction} {Change}</td><td>{PercentChange}</td></tr>';
21 
22     function formatStock(stock) {
23         return $.extend(stock, {
24             Price: stock.Price.toFixed(2),
25             PercentChange: (stock.PercentChange * 100).toFixed(2) + '%',
26             Direction: stock.Change === 0 ? '' : stock.Change >= 0 ? up : down
27         });
28     }
29 
30     function init() {
31         ticker.server.getAllStocks().done(function (stocks) {
32             $stockTableBody.empty();
33             $.each(stocks, function () {
34                 var stock = formatStock(this);
35                 $stockTableBody.append(rowTemplate.supplant(stock));
36             });
37         });
38     }
39 
40     function scrollTicker() {
41         var w = $stockTickerUl.width();
42         $stockTickerUl.css({ marginLeft: w });
43         $stockTickerUl.animate({ marginLeft: -w }, 15000, 'linear', scrollTicker);
44     }
45     // Add a client-side hub method that the server will call
46     ticker.client.updateStockPrice = function (stock) {
47         var displayStock = formatStock(stock),
48             $row = $(rowTemplate.supplant(displayStock));
49 
50         $stockTableBody.find('tr[data-symbol=' + stock.Symbol + ']')
51             .replaceWith($row);
52     }
53 
54     // Start the connection
55     $.connection.hub.start().done(init);
56 
57 });