Retrieve Currency Symbol from a String

Question

I am trying to retrieve an element from dropdown and storing in a string. I want to convert that string currency symbol to currency code. Following is the code i wrote:

I wrote below code but i am getting an error message :

System.Globalization.CultureNotFoundException: Culture is not supported. Parameter name: name USD - United States dollar is an invalid culture identifier.

public string RetreiveCurrencySymbolFromCode()
{
    string currencycode = " USD-United States Dollars";     
    string FinalCode = Currencycode1.Split('-')[0];      
    CultureInfo Symbol = new CultureInfo(FinalCode);
    return Symbol.NumberFormat.CurrencySymbol;
}

I expect to retrieve USD and change it to symbol $

Answer 1

Well, "USD" is name of a currency (RegionInfo.ISOCurrencySymbol), when "en-US" is an (expected) name of a culture (Culture.Name). Let's obtain all cultures that use USD as a currency:

  string FinalCode = "USD";

  var result = CultureInfo
    .GetCultures(CultureTypes.SpecificCultures)
    .Where(culture => new RegionInfo(culture.LCID).ISOCurrencySymbol == FinalCode)
    .ToArray();

  Console.Write(string.Join(Environment.NewLine, result
    .Select(culture => $"{culture.Name,10} : ({culture.NumberFormat.CurrencySymbol}) : {culture.EnglishName}")));

Outcome:

 en-US : ($) : English (United States)
quz-EC : ($) : Quechua (Ecuador)
en-029 : ($) : English (Caribbean)
 es-EC : ($) : Spanish (Ecuador)
 es-SV : ($) : Spanish (El Salvador)
 es-PR : ($) : Spanish (Puerto Rico)
 es-US : ($) : Spanish (United States)

As you can see several different cultures can use the same currency. Technically, you code can be implemented as

 using System.Text.RegularExpressions;

 ...

 string currencycode = " USD-United States Dollars";     

 ...

 // https://en.wikipedia.org/wiki/ISO_4217
 // ISO_4217 - all codes are 3 capital letters
 string FinalCode = Regex.Match(currencycode, "[A-Z]{3}").Value;

 var culture = CultureInfo
   .GetCultures(CultureTypes.SpecificCultures)
   .Where(culture => new RegionInfo(culture.LCID).ISOCurrencySymbol == FinalCode)
   .FirstOrDefault();

 if (culture != null) 
   return culture.NumberFormat.CurrencySymbol;
 else
   return "???"; // Unknown currency / culture

There are 2 issues here:

1. Currency code ISO 4217 is three capital letter combination (e.g. USD, EUR, RUB), a safier approach is to Match with a help of regular expressions
2. Same currency can be used by several cultures. You may want an additional rule to narrow down the required culture