Any libraries to convert number Pinyin to Pinyin with tone markings?

Just wondering if anyone knows of a 开发者_运维知识库class library that can convert Chinese Pinyin to ones with tones, such as nin2 hao3 ma to nín hǎo ma. It would be similar to this answer, but hopefully using the .NET framework.

Here is my porting of @Greg-Hewgill python algorithm to C#. I haven't run into any issues so far.

public static string ConvertNumericalPinYinToAccented(string input)
    {
        Dictionary<int, string> PinyinToneMark = new Dictionary<int, string>
        {
            {0, "aoeiuv\u00fc"},
            {1, "\u0101\u014d\u0113\u012b\u016b\u01d6\u01d6"},
            {2, "\u00e1\u00f3\u00e9\u00ed\u00fa\u01d8\u01d8"},
            {3, "\u01ce\u01d2\u011b\u01d0\u01d4\u01da\u01da"},
            {4, "\u00e0\u00f2\u00e8\u00ec\u00f9\u01dc\u01dc"}
        };

        string[] words = input.Split(' ');
        string accented = "";
        string t = "";
        foreach (string pinyin in words)
        {
            foreach (char c in pinyin)
            {
                if (c >= 'a' && c <= 'z')
                {
                    t += c;
                }
                else if (c == ':')
                {
                    if (t[t.Length - 1] == 'u')
                    {
                        t = t.Substring(0, t.Length - 2) + "\u00fc";
                    }
                }
                else
                {
                    if (c >= '0' && c <= '5')
                    {
                        int tone = (int)Char.GetNumericValue(c) % 5;

                        if (tone != 0)
                        {
                            Match match = Regex.Match(t, "[aoeiuv\u00fc]+");
                            if (!match.Success)
                            {
                                t += c;
                            }
                            else if (match.Groups[0].Length == 1)
                            {
                                t = t.Substring(0, match.Groups[0].Index) +
                                    PinyinToneMark[tone][PinyinToneMark[0].IndexOf(match.Groups[0].Value[0])]
                                    + t.Substring(match.Groups[0].Index + match.Groups[0].Length);
                            }
                            else
                            {
                                if (t.Contains("a"))
                                {
                                    t = t.Replace("a", PinyinToneMark[tone][0].ToString());
                                }
                                else if (t.Contains("o"))
                                {
                                    t = t.Replace("o", PinyinToneMark[tone][1].ToString());
                                }
                                else if (t.Contains("e"))
                                {
                                    t = t.Replace("e", PinyinToneMark[tone][2].ToString());
                                }
                                else if (t.Contains("ui"))
                                {
                                    t = t.Replace("i", PinyinToneMark[tone][3].ToString());
                                }
                                else if (t.Contains("iu"))
                                {
                                    t = t.Replace("u", PinyinToneMark[tone][4].ToString());
                                }
                                else
                                {
                                    t += "!";
                                }
                            }
                        }
                    }
                    accented += t;
                    t = "";
                }
            }
            accented += t + " ";
        }
        accented = accented.TrimEnd();
        return accented;
    }

I've used Microsoft Visual Studio International Pack.

This is 1.0 version. and Feature Pack 2.0.

Hope help you!

I think this line

t = t.Substring(0, t.Length - 2) + "\u00fc";

Should be this instead

t = t.Substring(0, t.Length - 1) + "\u00fc";