C# .NET - update currency price

For this you need to incorporate any web service providding these details...

Check here for more info...

http://www.portalsolutions.hu/docs/PortalSolutions_CurrencyUpdateWebService_SAP_6.20_ENG.pdf

and

http://www.xignite.com/xcurrencies.asmx?op=xServiceFAQ

U can use RSS feeds for update currency rate frequently in your site.

u can get RSS feed from valid site like

http://www.currencysource.com/rss_currencyexchangerates.html

and update frequently in your site

Jeff Prosise has written an article "http://webdeveloper.earthweb.com/webjs/print.php/10959_982451_5", he pretty much explained how to load XML data with ASP.NET from the "Rates.xml" file. In this article I have created Currency Converter Server which can be scheduled to extract the data from third party site and build the "Rates.xml" dynamically.

CurrencyConverter.dll Component:

"CurrencyConverter.dll" This component will extract the data from PACIFIC Exchange site using regular expression patterns.

      // html for which we are writing this regular expression pattern 
      /*
        <TD align=middle>ADP</TD>
        <TD align=left>Andorran Peseta</TD>
        <TD align=right>100.92</TD>
        <TD align=right>152.844</TD>
        <TD align=right>166.386</TD>
        <TD align=right>251.917</TD>
      */
      Regex regex = new Regex(@"<td.*?>(.+)</td>+", RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);

      MatchCollection matches = regex.Matches(rawHtml);

      if (matches.Count > 0) 
      {
        // Get the first match
        foreach(Match match in matches)
        {
          if (match.Success)
          {      
            // Get the second group in the match
            Group grp = match.Groups[1];
            
            // return data 
            Console.WriteLine(grp.Value);
          }
          
        }
      }

    XmlTextWriter writer = new XmlTextWriter(XMLFilePath, System.Text.Encoding.UTF8);
    
    writer.WriteStartDocument();

    //Use automatic indentation for readability.
    writer.Formatting = Formatting.Indented;
        
    //Write the root element
    writer.WriteStartElement("Rates");

    //Start an element
    writer.WriteStartElement("Rate");

    //add sub-elements
    writer.WriteElementString("Currency", "British Pound");
    writer.WriteElementString("Exchange", "0.635243");

    //End the item element
    writer.WriteEndElement();  // end Rate

    // end the root element
    writer.WriteFullEndElement();
             
    //Write the XML to file and close the writer
    writer.Flush();
    writer.Close(); 

  class BuildXML
  {
    static void Main()
    {

      string SupplementaryExchangeRatesActualSiteUrl = "http://pacific.commerce.ubc.ca/xr/rates.html";
      Currency cc = new Currency();
      cc.ExchangeRatesURL = SupplementaryExchangeRatesActualSiteUrl;
      cc.XMLFilePath = "Rates.xml";    
      cc.Build();
      Console.WriteLine(cc.ModuleError.ToString());
    }
  }

Here is the some site, from which exchange rate data can be extracted.

PACIFIC Exchange Rate Service for 242 countries
http://pacific.commerce.ubc.ca/xr/rates.html

PACIFIC Exchange daily Rates but limited countries
http://pacific.commerce.ubc.ca/xr/today.html

US Treasury Exchange Rates
http://www.fms.treas.gov/intn.html

Federal Reserve Bank Exchange Rates
http://www.federalreserve.gov/releases/H10/Update/

International Monetary Fund (IMF) Exchange Rates
http://www.imf.org/external/np/tre/sdr/db/rms_five.cfm

Rates.xml file:

"Rates.xml" contains 242 countries exchange rate. But if you look at the countries names they are not alphabetically sorted, I will explain this later how to sort data within ASP.NET page.

 <?xml version="1.0" encoding="utf-8"?>
<Rates>
  <Rate>
    <Currency>Andorran Peseta</Currency>
    <Exchange> 154.763</Exchange>
  </Rate>
  <Rate>
    <Currency>U.A.E. Dirham</Currency>
    <Exchange>   3.673</Exchange>
  </Rate>
  <Rate>
    <Currency>Afghanistan Afghani</Currency>
    <Exchange>  42.785</Exchange>
  </Rate>
  <Rate>
    <Currency>Albanian Lek</Currency>
    <Exchange> 129.181</Exchange>
  </Rate>
  <Rate>
    <Currency>Armenia Dram</Currency>
    <Exchange> 554.882</Exchange>
  </Rate>
  <Rate>
    <Currency>Neth. Ant. Guilder</Currency>
    <Exchange>    1.78</Exchange>
  </Rate>
  <Rate>
    <Currency>Angolan Kwanza</Currency>
    <Exchange> 65.0163</Exchange>
  </Rate>
  <Rate>
    <Currency>Argentine Peso</Currency>
    <Exchange>   3.155</Exchange>
  </Rate>
  <Rate>
    <Currency>Austrian Schilling</Currency>
    <Exchange> 12.7991</Exchange>
  </Rate>
  <Rate>
    <Currency>Christmas Is. Dollar</Currency>
    <Exchange> 1.65399</Exchange>
  </Rate>
  <Rate>
    <Currency>Cocos(Keeling) Is.</Currency>
    <Exchange> 1.65399</Exchange>
  </Rate>
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SOURCE FROM : http://www.csharphelp.com/archives2/archive441.html

See these articles for Current Converter and updates

http://www.csharphelp.com/archives2/archive441.html

http://www.codeproject.com/KB/aspnet/currency_convertor_ws.aspx

Hope this helps.