c# 得到汉字首字母/转换字符

private void getFirstCode()
        {
            Num = 0;
            conn = "Provider=SQLNCLI;Data Source=192.168.0.111,1433;Database=MIS;UID=sa;PWD=;";
            string WordBegin = "";
            string TermName = "";
            sql = "select Term_Name from terms where word_begin is null";
            OleDbDataReader odr = db.GetList(conn, sql);
            while (odr.Read())
            {
                Num++;
                txt_num.Text = Num.ToString();
                TermName = odr.GetValue(0).ToString();
                WordBegin = GetChineseSpell(TermName).Substring(0, 1);
                sql = "update terms set Word_Begin='" + modsql(WordBegin) + "' where Term_Name='" + modsql(TermName) + "'";
                db.ExeSql(conn, sql);
            }
            MessageBox.Show("获取完成！");
        }
static public string GetChineseSpell(string strText)
  {
   int len = strText.Length;
   string myStr = "";
   for(int i=0;i<len;i++)
   {
    myStr += getSpell(strText.Substring(i,1));
   }
   return myStr;
  }

  static public string getSpell(string cnChar)
  {
   byte[] arrCN = Encoding.Default.GetBytes(cnChar);
   if(arrCN.Length > 1)
   {
    int area = (short)arrCN[0];
    int pos = (short)arrCN[1];
    int code = (area<<8) + pos;
    int[] areacode = {45217,45253,45761,46318,46826,47010,47297,47614,48119,48119,49062,49324,49896,50371,50614,50622,50906,51387,51446,52218,52698,52698,52698,52980,53689,54481};
    for(int i=0;i<26;i++)
    {
     int max = 55290;
     if(i != 25) max = areacode[i+1];
     if(areacode[i]<=code && code<max)
     {
      return Encoding.Default.GetString(new byte[]{(byte)(65+i)});
     }
    }
    return "*";
   }
   else return cnChar;
  }

//转换字符

private string UnicodeToGB(string content)
        {
            Regex objRegex = new Regex("&#(?<UnicodeCode>[\\d]{5});", RegexOptions.IgnoreCase);
            Match objMatch = objRegex.Match(content);
            StringBuilder sb = new StringBuilder(content);
            while (objMatch.Success)
            {
                string code = Convert.ToString(Convert.ToInt32(objMatch.Result("${UnicodeCode}")), 16);
                byte[] array = new byte[2];
                array[0] = (byte)Convert.ToInt32(code.Substring(2), 16);
                array[1] = (byte)Convert.ToInt32(code.Substring(0, 2), 16);

                sb.Replace(objMatch.Value, Encoding.Unicode.GetString(array));

                objMatch = objMatch.NextMatch();
            }
            return sb.ToString();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            MessageBox.Show(UnicodeToGB("\u8bf7\u6c42\u6709\u6b63\u4e49\u611f\u7684\u597d\u5fc3\u4eba\u5e2e\u5e2e\u6211."));
        }
//此方法转换Unicode到汉字
private string UnicodeToCN(string content)
        {
            string str = content.Replace(@"\u","");
            string temp = string.Empty;
            for (int i = 0; i < str.Length / 4; i++)
            {
                temp += (char)Convert.ToInt32(str.Substring(i * 4, 4), 16);
            }
           return temp;
        }

//另种方法转换

 1using System.Text.RegularExpressions;
 2
 3/**//// <summary>
 4/// 将Unicode转找为Character
 5/// </summary>
 6/// <param name="str">原字符串</param>
 7/// <returns></returns>
 8private string Unicode2Character(string str)
 9{
10    string text = str;
11    string strPattern = "(?<code>\\\\u[A-F0-9]{4})";
12    do
13    {
14        Match m = Regex.Match(text, strPattern, RegexOptions.IgnoreCase);
15        if (m.Success)
16        {
17            string strValue = m.Groups["code"].Value;
18            int i = System.Int32.Parse(strValue.Substring(2, 4), System.Globalization.NumberStyles.HexNumber);
19            char ch = Convert.ToChar(i);
20            text = text.Replace(strValue, ch.ToString());
21        }
22        else
23        {
24            break;
25        }
26    }
27    while(true);
28
29    return text;
30}