Asp.net 通过 RSS 获取货币汇率
3.32/5 (7投票s)
2007年6月21日
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本文档旨在解释如何使用实时 XML 来显示数据。我使用了 currencysource.com 的汇率来展示这种技术的一种应用。代码中包含了一些注释来解释其工作原理。
引言
这段代码使用一个 RSS 提要，提供最新的货币汇率，并在用户点击“获取”按钮时从中提取数据。用户可以选择要获取汇率的货币。这段代码很有用，因为它获取了最新的货币汇率信息——这是处理商业应用系统越来越期望的功能。
背景
这段代码使用 ASP .Net 2.0、C# 2.0，并展示了 Prototype.js（一个第三方 Javascript 框架）的实用性。
使用代码
代码后端的代码作为参考提供，之后是 HTML 代码。
//using System; //using System.Data; //using System.Configuration; //using System.Collections; //using System.Web; //using System.Web.Security; //using System.Web.UI; //using System.Web.UI.WebControls; //using System.Web.UI.WebControls.WebParts; //using System.Web.UI.HtmlControls; //using System.Xml; //public partial class Modules_LiveExchangeRates : System.Web.UI.Page //{ // protected void Page_Load(object sender, EventArgs e) // { // if (!Page.IsPostBack) // { // } // } // private void PopulateGrid(string vstrURL) // { // if (lstExchange.Items.Count > 0) // { // lstExchange.Items.Clear(); // } // XmlDocument objDoc = new XmlDocument(); // objDoc.Load(vstrURL); // XmlNodeList objNL; // if (null != objDoc) // { // objNL = objDoc.SelectNodes("rss/channel/item"); // if (null != objNL) // { // foreach (XmlNode XNode in objNL) // { // lstExchange.Items.Add(XNode.ChildNodes[0].InnerText); // } // } // } // } // protected void btnFetchValue_Click(object sender, EventArgs e) // { // PopulateGrid(txtURL.Text.Trim()); // } //} //----------- HTML Code //<html xmlns="http://www.w3.org/1999/xhtml" > //<head id="Head1" runat="server"> // <title>Page</title> // <link href="../Styles/StyleSheet.css" rel="stylesheet" type="text/css" /> // <script type="text/javascript" src="../scripts/prototype.js"></script> // <script type="text/javascript"> // <!-- //function Rvalue() { // document.getElementById("rssText").innerHTML = "Copy URL into RSS Application...<br>" + document.frmPage["rss"].value; // $("txtURL").value=$("rss").value; //} //--> </script> <style type="text/css"> <!-- //.graybox { //border: solid 1px gray; //} //#graybox { //border: solid 1px gray; //} //.rssText { // font-family: Arial, Helvetica, sans-serif; font-size: 0.8em; color: #333399; //} //#smlink { //font-size: .6em; //color: #dedede; //font-style: normal; //font-family: Arial, Helvetica, sans-serif; //} //#smlink a:link,#smlink a:visited{ //color: #7e7e7e; /*Was #dedede.*/ //text-decoration: none; } //#smlink a:hover { //color: #7e7e7e; //text-decoration: underline} //--> </style> //</head> //<body> // <form id="frmPage" runat="server"> // <table id="tblMain" style="width:100%" class="tablebdr1"> // <tr> // <td style="height:20px" class="textorg">Live Exchage Rates</td> // </tr> // <tr> // <td style="height:20px"></td> // </tr> // <tr> // <td> // <table border="0" cellspacing="2" cellpadding="2" id="graybox" style="width: 273px; height: 74px"> // <tr> <td class="textorg"><div align="center"> // Currency Exchange Rates via <b>RSS</b></div></td></tr><tr><td> //<select name="rss" onchange="javascript:Rvalue()"> // <option value="0" selected="selected">Select a Currency...</option> // <option value="http://currencysource.com/RSS/ARS.xml">Argentine Peso</option> // <option value="http://currencysource.com/RSS/AUD.xml">Australian Dollar</option> // <option value="http://currencysource.com/RSS/BHD.xml">Bahrain Dinar</option> // <option value="http://currencysource.com/RSS/BWP.xml">Botswana Pula</option> // <option value="http://currencysource.com/RSS/BRL.xml">Brazilian Real</option> // <option value="http://currencysource.com/RSS/BND.xml">Brunei Dollar</option> // <option value="http://currencysource.com/RSS/CAD.xml">Canadian Dollar</option> // <option value="http://currencysource.com/RSS/CLP.xml">Chilian Peso</option> // <option value="http://currencysource.com/RSS/CNY.xml">Chinese Yuan</option> // <option value="http://currencysource.com/RSS/COP.xml">Colombian Peso</option> // <option value="http://currencysource.com/RSS/CYP.xml">Cyprus Pound</option> // <option value="http://currencysource.com/RSS/CZK.xml">Czech Koruna</option> // <option value="http://currencysource.com/RSS/DKK.xml">Danish Krone</option> // <option value="http://currencysource.com/RSS/EUR.xml">Euro</option> // <option value="http://currencysource.com/RSS/HUF.xml">Hungarian Forint</option> // <option value="http://currencysource.com/RSS/ISK.xml">Icelandic Krona</option> // <option value="http://currencysource.com/RSS/INR.xml">Indian Rupee</option> // <option value="http://currencysource.com/RSS/IDR.xml">Indonesian Rupiah</option> // <option value="http://currencysource.com/RSS/IRR.xml">Iranian Rial</option> // <option value="http://currencysource.com/RSS/ILS.xml">Israeli New Sheqel</option> // <option value="http://currencysource.com/RSS/JPY.xml">Japanese Yen</option> // <option value="http://currencysource.com/RSS/KRW.xml">Korean Won</option> // <option value="http://currencysource.com/RSS/KWD.xml">Kuwaiti Dinar</option> // <option value="http://currencysource.com/RSS/LYD.xml">Libyan Dinar</option> // <option value="http://currencysource.com/RSS/MYR.xml">Malaysian Ringgit</option> // <option value="http://currencysource.com/RSS/MTL.xml">Maltese Lira</option> // <option value="http://currencysource.com/RSS/MUR.xml">Mauritian Rupee</option> // <option value="http://currencysource.com/RSS/MXN.xml">Mexican Peso</option> // <option value="http://currencysource.com/RSS/NPR.xml">Nepalese Rupee</option> // <option value="http://currencysource.com/RSS/NZD.xml">New Zealand Dollar</option> // <option value="http://currencysource.com/RSS/NOK.xml">Norwegian Krone</option> // <option value="http://currencysource.com/RSS/OMR.xml">Omani Rial</option> // <option value="http://currencysource.com/RSS/PKR.xml">Pakistan Rupee</option> // <option value="http://currencysource.com/RSS/PLN.xml">Polish Zloty</option> // <option value="http://currencysource.com/RSS/GBP.xml">Pound Sterling</option> // <option value="http://currencysource.com/RSS/QAR.xml">Qatar Riyal</option> // <option value="http://currencysource.com/RSS/SAR.xml">Saudi Arabian Riyal</option> // <option value="http://currencysource.com/RSS/SGD.xml">Singapore Dollar</option> // <option value="http://currencysource.com/RSS/SIT.xml">Slovenian Tolar</option> // <option value="http://currencysource.com/RSS/ZAR.xml">South African Rand</option> // <option value="http://currencysource.com/RSS/LKR.xml">Sri Lanka Rupee</option> // <option value="http://currencysource.com/RSS/SEK.xml">Swedish Krona</option> // <option value="http://currencysource.com/RSS/SEK.xml">Swiss Franc</option> // <option value="http://currencysource.com/RSS/THB.xml">Thai Baht</option> // <option value="http://currencysource.com/RSS/TTD.xml">Trinidad & Tobago Dollar</option> // <option value="http://currencysource.com/RSS/AED.xml">U.A.E. Dirham</option> // <option value="http://currencysource.com/RSS/USD.xml">U.S. Dollar</option> // <option value="http://currencysource.com/RSS/VEB.xml">Venezuelan Bolivar</option> //</select> //</td> // </tr> // <tr style="display:none"> // <td> // <div align="left"> // </div> // <div id="rssText" align="left" class="textorg"> //// URL: // </div> // <asp:TextBox ID="txtURL" runat="server" Text=""></asp:TextBox> // </td> // </tr> // </table> // <!-- That's it! Your site visitors now have access to continuously updated Currency Exchange Rates via RSS! --> //<asp:Button ID="btnFetchValue" runat="server" Text="Fetch Value" OnClick="btnFetchValue_Click" /></td> // </tr> // <tr> // <td> // <asp:ListBox ID="lstExchange" runat="server" Width="363px" Height="456px"></asp:ListBox> // </td> // </tr> // </table> // </form> //</body> //</html>
请记得使用语言下拉菜单设置代码片段的语言。
使用“var”按钮来将变量或类名包裹在 <code> 标签中，例如 this。