c#中如何得到汉字的拼音首字母

添加命名空间
using System.Text.RegularExpressions;
  
///  

 
///   判断是否为汉字  
///  

 
///   待检测字符串  
///   是汉字返回true  
public bool IsChineseCharacters(string chrStr)
{
    Regex CheckStr = new Regex("[/u4e00-/u9fa5]");
    return CheckStr.IsMatch(chrStr);
}

///

/// 得到每个汉字的字首拼音码字母(大写)
///

/// 输入字符串
/// 返回结果
public string GetHeadCharacter(string chrStr)
{
    string strHeadString = string.Empty;

    Encoding gb = System.Text.Encoding.GetEncoding("gb2312");
    for (int i = 0; i < chrStr.Length; i++)
    {
        //检测该字符是否为汉字
        if(!IsChineseCharacters(chrStr.Substring(i, 1)))
        {
            strHeadString += chrStr.Substring(i, 1);
            continue;
        }

        byte[] bytes = gb.GetBytes(chrStr.Substring(i, 1));
        string lowCode = System.Convert.ToString(bytes[0] - 0xA0, 16);
        string hightCode = System.Convert.ToString(bytes[1] - 0xA0, 16);
        int nCode = Convert.ToUInt16(lowCode, 16) * 100 + Convert.ToUInt16(hightCode, 16);      //得到区位码
        strHeadString += FirstLetter(nCode);
    }
    return strHeadString;
}

///

/// 通过汉字区位码得到其首字母(大写)
///

/// 汉字编码
///
public string FirstLetter(int nCode)
{
    if (nCode >= 1601 && nCode < 1637) return "A";
    if (nCode >= 1637 && nCode < 1833) return "B";
    if (nCode >= 1833 && nCode < 2078) return "C";
    if (nCode >= 2078 && nCode < 2274) return "D";
    if (nCode >= 2274 && nCode < 2302) return "E";
    if (nCode >= 2302 && nCode < 2433) return "F";
    if (nCode >= 2433 && nCode < 2594) return "G";
    if (nCode >= 2594 && nCode < 2787) return "H";
    if (nCode >= 2787 && nCode < 3106) return "J";
    if (nCode >= 3106 && nCode < 3212) return "K";
    if (nCode >= 3212 && nCode < 3472) return "L";
    if (nCode >= 3472 && nCode < 3635) return "M";
    if (nCode >= 3635 && nCode < 3722) return "N";
    if (nCode >= 3722 && nCode < 3730) return "O";
    if (nCode >= 3730 && nCode < 3858) return "P";
    if (nCode >= 3858 && nCode < 4027) return "Q";
    if (nCode >= 4027 && nCode < 4086) return "R";
    if (nCode >= 4086 && nCode < 4390) return "S";
    if (nCode >= 4390 && nCode < 4558) return "T";
    if (nCode >= 4558 && nCode < 4684) return "W";
    if (nCode >= 4684 && nCode < 4925) return "X";
    if (nCode >= 4925 && nCode < 5249) return "Y";
    if (nCode >= 5249 && nCode < 5590) return "Z";
    return "";
    }
}