Since Dimi set the bounty and needs a more "modern" solution, I will try to provide it. First, what do we need from a reasonable class that converts strings to different things?
Reasonable behavior with basic types.
View cultural information, especially when converting numbers and dates.
The ability to extend logic with custom converters, if necessary.
As a bonus, avoid long if-chains as they are quite error prone.
public class StringConverter { // delegate for TryParse(string, out T) public delegate bool TypedConvertDelegate<T>(string value, out T result); // delegate for TryParse(string, out object) private delegate bool UntypedConvertDelegate(string value, out object result); private readonly List<UntypedConvertDelegate> _converters = new List<UntypedConvertDelegate>(); // default converter, lazyly initialized private static readonly Lazy<StringConverter> _default = new Lazy<StringConverter>(CreateDefault, true); public static StringConverter Default => _default.Value; private static StringConverter CreateDefault() { var d = new StringConverter(); // add reasonable default converters for common .NET types. Don't forget to take culture into account, that's // important when parsing numbers\dates. d.AddConverter<bool>(bool.TryParse); d.AddConverter((string value, out byte result) => byte.TryParse(value, NumberStyles.Integer, d.Culture, out result)); d.AddConverter((string value, out short result) => short.TryParse(value, NumberStyles.Integer, d.Culture, out result)); d.AddConverter((string value, out int result) => int.TryParse(value, NumberStyles.Integer, d.Culture, out result)); d.AddConverter((string value, out long result) => long.TryParse(value, NumberStyles.Integer, d.Culture, out result)); d.AddConverter((string value, out float result) => float.TryParse(value, NumberStyles.Number, d.Culture, out result)); d.AddConverter((string value, out double result) => double.TryParse(value, NumberStyles.Number, d.Culture, out result)); d.AddConverter((string value, out DateTime result) => DateTime.TryParse(value, d.Culture, DateTimeStyles.None, out result)); return d; } // public CultureInfo Culture { get; set; } = CultureInfo.CurrentCulture; public void AddConverter<T>(Predicate<string> match, Func<string, T> converter) { // create converter from match predicate and convert function _converters.Add((string value, out object result) => { if (match(value)) { result = converter(value); return true; } result = null; return false; }); } public void AddConverter<T>(Regex match, Func<string, T> converter) { // create converter from match regex and convert function _converters.Add((string value, out object result) => { if (match.IsMatch(value)) { result = converter(value); return true; } result = null; return false; }); } public void AddConverter<T>(TypedConvertDelegate<T> constructor) { // create converter from typed TryParse(string, out T) function _converters.Add(FromTryPattern<T>(constructor)); } public bool TryConvert(string value, out object result) { if (this != Default) { // if this is not a default converter - first try convert with default if (Default.TryConvert(value, out result)) return true; } // then use local converters. Any will return after the first match object tmp = null; bool anyMatch = _converters.Any(c => c(value, out tmp)); result = tmp; return anyMatch; } private static UntypedConvertDelegate FromTryPattern<T>(TypedConvertDelegate<T> inner) { return (string value, out object result) => { T tmp; if (inner.Invoke(value, out tmp)) { result = tmp; return true; } else { result = null; return false; } }; } }
Use this:
static void Main(string[] args) { // set culture to invariant StringConverter.Default.Culture = CultureInfo.InvariantCulture; // add custom converter to default, it will match strings starting with CUSTOM: and return MyCustomClass StringConverter.Default.AddConverter(c => c.StartsWith("CUSTOM:"), c => new MyCustomClass(c)); var items = new[] {"1", "4343434343", "3.33", "true", "false", "2014-10-10 22:00:00", "CUSTOM: something"}; foreach (var item in items) { object result; if (StringConverter.Default.TryConvert(item, out result)) { Console.WriteLine(result); } } // create new non-default converter var localConverter = new StringConverter(); // add custom converter to parse json which matches schema for MySecondCustomClass localConverter.AddConverter((string value, out MySecondCustomClass result) => TryParseJson(value, @"{'value': {'type': 'string'}}", out result)); { object result; // check if that works if (localConverter.TryConvert("{value: \"Some value\"}", out result)) { Console.WriteLine(((MySecondCustomClass) result).Value); } } Console.ReadKey(); } static bool TryParseJson<T>(string json, string rawSchema, out T result) where T : new() { // we are using Newtonsoft.Json here var parsedSchema = JsonSchema.Parse(rawSchema); JObject jObject = JObject.Parse(json); if (jObject.IsValid(parsedSchema)) { result = JsonConvert.DeserializeObject<T>(json); return true; } else { result = default(T); return false; } } class MyCustomClass { public MyCustomClass(string value) { this.Value = value; } public string Value { get; private set; } } public class MySecondCustomClass { public string Value { get; set; } }