Converting country codes in .NET
Looks like there is no built-in way to do that. You can use the approach from the GenericTypeTea's answer. But if you need to convert many country codes you can avoid Cultures enumeration and pre-compute a mapping dictionary for country codes conversion.
That's how such generator looks like:
namespace ISOCountryCodes
{
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
class Program
{
public static void Main(string[] args)
{
var countryCodesMapping = new Dictionary<string, RegionInfo>();
CultureInfo[] cultures = CultureInfo.GetCultures(CultureTypes.SpecificCultures);
foreach (var culture in cultures)
{
try
{
var region = new RegionInfo(culture.LCID);
countryCodesMapping[region.ThreeLetterISORegionName] = region;
}
catch (CultureNotFoundException)
{
var consoleColor = Console.ForegroundColor;
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Culture not found: " + culture.Name);
Console.ForegroundColor = consoleColor;
}
}
Console.WriteLine("var countryCodesMapping = new Dictionary<string, string>() {");
foreach (var mapping in countryCodesMapping.OrderBy(mapping => mapping.Key))
{
Console.WriteLine(" {{ \"{0}\", \"{1}\" }}, // {2}", mapping.Key, mapping.Value.TwoLetterISORegionName, mapping.Value.EnglishName);
}
Console.WriteLine("};");
}
}
}
Run this generator to get a country codes mapping dictionary like this:
var countryCodesMapping = new Dictionary<string, string>() {
{ "AFG", "AF" }, // Afghanistan
{ "ALB", "AL" }, // Albania
{ "ARE", "AE" }, // U.A.E.
{ "ARG", "AR" }, // Argentina
{ "ARM", "AM" }, // Armenia
{ "AUS", "AU" }, // Australia
{ "AUT", "AT" }, // Austria
{ "AZE", "AZ" }, // Azerbaijan
{ "BEL", "BE" }, // Belgium
{ "BGD", "BD" }, // Bangladesh
{ "BGR", "BG" }, // Bulgaria
{ "BHR", "BH" }, // Bahrain
{ "BIH", "BA" }, // Bosnia and Herzegovina
{ "BLR", "BY" }, // Belarus
{ "BLZ", "BZ" }, // Belize
{ "BOL", "BO" }, // Bolivia
{ "BRA", "BR" }, // Brazil
{ "BRN", "BN" }, // Brunei Darussalam
{ "CAN", "CA" }, // Canada
{ "CHE", "CH" }, // Switzerland
{ "CHL", "CL" }, // Chile
{ "CHN", "CN" }, // People's Republic of China
{ "COL", "CO" }, // Colombia
{ "CRI", "CR" }, // Costa Rica
{ "CZE", "CZ" }, // Czech Republic
{ "DEU", "DE" }, // Germany
{ "DNK", "DK" }, // Denmark
{ "DOM", "DO" }, // Dominican Republic
{ "DZA", "DZ" }, // Algeria
{ "ECU", "EC" }, // Ecuador
{ "EGY", "EG" }, // Egypt
{ "ESP", "ES" }, // Spain
{ "EST", "EE" }, // Estonia
{ "ETH", "ET" }, // Ethiopia
{ "FIN", "FI" }, // Finland
{ "FRA", "FR" }, // France
{ "FRO", "FO" }, // Faroe Islands
{ "GBR", "GB" }, // United Kingdom
{ "GEO", "GE" }, // Georgia
{ "GRC", "GR" }, // Greece
{ "GRL", "GL" }, // Greenland
{ "GTM", "GT" }, // Guatemala
{ "HKG", "HK" }, // Hong Kong S.A.R.
{ "HND", "HN" }, // Honduras
{ "HRV", "HR" }, // Croatia
{ "HUN", "HU" }, // Hungary
{ "IDN", "ID" }, // Indonesia
{ "IND", "IN" }, // India
{ "IRL", "IE" }, // Ireland
{ "IRN", "IR" }, // Iran
{ "IRQ", "IQ" }, // Iraq
{ "ISL", "IS" }, // Iceland
{ "ISR", "IL" }, // Israel
{ "ITA", "IT" }, // Italy
{ "JAM", "JM" }, // Jamaica
{ "JOR", "JO" }, // Jordan
{ "JPN", "JP" }, // Japan
{ "KAZ", "KZ" }, // Kazakhstan
{ "KEN", "KE" }, // Kenya
{ "KGZ", "KG" }, // Kyrgyzstan
{ "KHM", "KH" }, // Cambodia
{ "KOR", "KR" }, // Korea
{ "KWT", "KW" }, // Kuwait
{ "LAO", "LA" }, // Lao P.D.R.
{ "LBN", "LB" }, // Lebanon
{ "LBY", "LY" }, // Libya
{ "LIE", "LI" }, // Liechtenstein
{ "LKA", "LK" }, // Sri Lanka
{ "LTU", "LT" }, // Lithuania
{ "LUX", "LU" }, // Luxembourg
{ "LVA", "LV" }, // Latvia
{ "MAC", "MO" }, // Macao S.A.R.
{ "MAR", "MA" }, // Morocco
{ "MCO", "MC" }, // Principality of Monaco
{ "MDV", "MV" }, // Maldives
{ "MEX", "MX" }, // Mexico
{ "MKD", "MK" }, // Macedonia (FYROM)
{ "MLT", "MT" }, // Malta
{ "MNE", "ME" }, // Montenegro
{ "MNG", "MN" }, // Mongolia
{ "MYS", "MY" }, // Malaysia
{ "NGA", "NG" }, // Nigeria
{ "NIC", "NI" }, // Nicaragua
{ "NLD", "NL" }, // Netherlands
{ "NOR", "NO" }, // Norway
{ "NPL", "NP" }, // Nepal
{ "NZL", "NZ" }, // New Zealand
{ "OMN", "OM" }, // Oman
{ "PAK", "PK" }, // Islamic Republic of Pakistan
{ "PAN", "PA" }, // Panama
{ "PER", "PE" }, // Peru
{ "PHL", "PH" }, // Republic of the Philippines
{ "POL", "PL" }, // Poland
{ "PRI", "PR" }, // Puerto Rico
{ "PRT", "PT" }, // Portugal
{ "PRY", "PY" }, // Paraguay
{ "QAT", "QA" }, // Qatar
{ "ROU", "RO" }, // Romania
{ "RUS", "RU" }, // Russia
{ "RWA", "RW" }, // Rwanda
{ "SAU", "SA" }, // Saudi Arabia
{ "SCG", "CS" }, // Serbia and Montenegro (Former)
{ "SEN", "SN" }, // Senegal
{ "SGP", "SG" }, // Singapore
{ "SLV", "SV" }, // El Salvador
{ "SRB", "RS" }, // Serbia
{ "SVK", "SK" }, // Slovakia
{ "SVN", "SI" }, // Slovenia
{ "SWE", "SE" }, // Sweden
{ "SYR", "SY" }, // Syria
{ "TAJ", "TJ" }, // Tajikistan
{ "THA", "TH" }, // Thailand
{ "TKM", "TM" }, // Turkmenistan
{ "TTO", "TT" }, // Trinidad and Tobago
{ "TUN", "TN" }, // Tunisia
{ "TUR", "TR" }, // Turkey
{ "TWN", "TW" }, // Taiwan
{ "UKR", "UA" }, // Ukraine
{ "URY", "UY" }, // Uruguay
{ "USA", "US" }, // United States
{ "UZB", "UZ" }, // Uzbekistan
{ "VEN", "VE" }, // Bolivarian Republic of Venezuela
{ "VNM", "VN" }, // Vietnam
{ "YEM", "YE" }, // Yemen
{ "ZAF", "ZA" }, // South Africa
{ "ZWE", "ZW" }, // Zimbabwe
};
The RegionInfo class does know the three-letter code (in the ThreeLetterISORegionName property), but I don’t think there is a way to get RegionInfo based on this code, you would need to enumerate all regions and add them to your own dictionary, with the three-letter code as a key.
However, I think the .NET Framework uses RegionInfo to work with cultures, not countries in the ISO 3166-1 sense. Therefore, many countries from the ISO 3166-1 standard are not available (try e.g. SX). I guess you should create your own country codebook.
Edit: From 246 countries in my current country codebook, RegionInfo is available for 125 of them, the rest (121) are not supported. Conclusion: This is not a good way to get a country codebook.
UPDATED:
Didn't read the question properly before. The following should now be correctly converting from ISO 3166-1 alpha-3 to ISO 3166-1 alpha-2:
There's no built in way of doing it. You'll need to iterate through the CultureInfos to get the RegionInfos in order to manually find the match (this is pretty ineffecient so some caching would be advisable):
public string ConvertThreeLetterNameToTwoLetterName(string name)
{
if (name.Length != 3)
{
throw new ArgumentException("name must be three letters.");
}
name = name.ToUpper();
CultureInfo[] cultures = CultureInfo.GetCultures(CultureTypes.SpecificCultures);
foreach (CultureInfo culture in cultures)
{
RegionInfo region = new RegionInfo(culture.LCID);
if (region.ThreeLetterISORegionName.ToUpper() == name)
{
return region.TwoLetterISORegionName;
}
}
return null;
}