C#: Partially supported string interpolation (for backward compatibility)

StringFormatter.cs

using System.Collections.Generic;
using System.Text.RegularExpressions;

public static class StringFormatter {
  /// <summary>
  /// How to use:
  /// <code>
  /// var args = new Dictionary&lt;string, string&gt; {
  /// 	{ "test", "def" }
  /// };
  /// var str = StringFormatter.Format("abc {test} ghi", args);
  /// Console.WriteLine(str); // abc def ghi
  /// </code>
  /// </summary>
  /// <param name="format"></param>
  /// <param name="args"></param>
  /// <returns></returns>
  public static string Format(string format, Dictionary<string, string> args) {
    if (string.IsNullOrEmpty(format) || args == null) {
      return format;
    }
    Regex regex = new Regex(@"{{|}}|{([^}]+)}");
    return regex.Replace(format, (Match match) => {
      switch (match.Value) {
        case "{{":
          return "{";
        case "}}":
          return "}";
      }
      if (match.Groups.Count < 2) {
        return string.Empty;
      }
      string value = match.Groups[1].Value;
      if (args.ContainsKey(value) == false) {
        return string.Empty;
      }
      return args[value];
    });
  }
}