C#中把中文字符替换为*

方法一
http: // blog.youkuaiyun.com/qiujiahao/archive/2007/08/09/1733169.aspx
在unicode 字符串中，中文的范围是在4E00..9FFF:CJK Unified Ideographs。

通过对字符的unicode编码进行判断来确定字符是否为中文。


protected bool   IsChineseLetter( string input, int index)
    ...{
        int code = 0 ;
        int chfrom = Convert.ToInt32( " 4e00 " , 16 );    // 范围（0x4e00～0x9fff）转换成int（chfrom～chend）
        int chend = Convert.ToInt32( " 9fff " , 16 );
        if (input != "" )
        ...{
            code = Char.ConvertToUtf32(input, index);    // 获得字符串input中指定索引index处字符unicode编码
           
           if (code >= chfrom && code <= chend)    
            ...{
                return true ;     // 当code在中文范围内返回true

            }
            else
            ...{
                 return false ;    // 当code不在中文范围内返回false
            }
        }
          return false ;
}

方法二：
http: // hi.baidu.com/yhfd/blog/item/3222e1fca22cfb80b901a027.html
public bool IsChina( string CString)
          {
              bool BoolValue = false ;
              for ( int i = 0 ; i < CString.Length; i ++ )
              {
                  if (Convert.ToInt32(Convert.ToChar(CString.Substring(i, 1 ))) < Convert.ToInt32(Convert.ToChar( 128 )))
                  {
                      BoolValue = false ;
                  }
                  else
                  {
                      return BoolValue = true ;
                  }
              }
              return BoolValue;
          }

方法三：

        /// <summary>
        /// 判断句子中是否含有中文     宁夏大学 张冬 zd4004.blog.163.com
        /// </summary>
        /// <param > 字符串 </param>
        public bool WordsIScn( string words)
        {
            string TmmP;

            for ( int i = 0 ; i < words.Length; i ++ )
            {
                TmmP = words.Substring(i, 1 );

                byte [] sarr = System.Text.Encoding.GetEncoding( " gb2312 " ).GetBytes(TmmP);

                if (sarr.Length == 2 )
                {
                    return true ;
                }
            }
            return false ;
        }



方法四：
for ( int i = 0 ; i < s.length; i ++ )
{
Regex rx = new Regex( " ^[/u4e00-/u9fa5]$ " );
if (rx.IsMatch(s[i]))
// 是
else
// 否
}
正解！
/u4e00 - /u9fa5 汉字的范围。
^ [/u4e00 - /u9fa5]$ 汉字的范围的正则

方法五
unicodeencoding   unicodeencoding   =    new    unicodeencoding();  
  byte    []   unicodebytearray   =    unicodeencoding.getbytes(   inputstring   );  
  for (   int    i   =    0 ;   i   <    unicodebytearray.length;   i ++    )  
  {  
  i ++ ;  
  // 如果是中文字符那么高位不为0  
  if    (   unicodebytearray[i]   !=    0    )  
  {  
  }  
  ……  

方法六
    /// <summary>
        /// 给定一个字符串，判断其是否只包含有汉字
        /// </summary>
        /// <param name="testStr"></param>
        /// <returns></returns>
        public bool IsOnlyContainsChinese( string testStr)
        {
            char [] words = testStr.ToCharArray();
            foreach ( char word in words)
            {
                if ( IsGBCode(word.ToString()) || IsGBKCode(word.ToString()) )  // it is a GB2312 or GBK chinese word
                {
                    continue ;
                }
                else
                {
                    return false ;
                }
            }
            return true ;
        }
        /// <summary>
        /// 判断一个word是否为GB2312编码的汉字
        /// </summary>
        /// <param name="word"></param>
        /// <returns></returns>
        private bool IsGBCode( string word)
        {
            byte [] bytes = Encoding.GetEncoding( " GB2312 " ).GetBytes(word);
            if (bytes.Length <= 1 )  // if there is only one byte, it is ASCII code or other code
            {
                return false ;
            }
            else
            {
                byte byte1 = bytes[ 0 ];
                byte byte2 = bytes[ 1 ];
                if (byte1 >= 176 && byte1 <= 247 && byte2 >= 160 && byte2 <= 254 )    // 判断是否是GB2312
                {
                    return true ;
                }
                else
                {
                    return false ;
                }
            }
        }

        /// <summary>
        /// 判断一个word是否为GBK编码的汉字
        /// </summary>
        /// <param name="word"></param>
        /// <returns></returns>
        private bool IsGBKCode( string word)
        {
            byte [] bytes = Encoding.GetEncoding( " GBK " ).GetBytes(word.ToString());
            if (bytes.Length <= 1 )  // if there is only one byte, it is ASCII code
            {
                return false ;
            }
            else
            {
                byte byte1 = bytes[ 0 ];
                byte byte2 = bytes[ 1 ];
                if ( byte1 >= 129 && byte1 <= 254 && byte2 >= 64 && byte2 <= 254 )     // 判断是否是GBK编码
                {
                    return true ;
                }
                else
                {
                    return false ;
                }
            }
        }

 

        /// <summary>
        /// 判断一个word是否为Big5编码的汉字
        /// </summary>
        /// <param name="word"></param>
        /// <returns></returns>
        private bool IsBig5Code( string word)
        {
            byte [] bytes = Encoding.GetEncoding( " Big5 " ).GetBytes(word.ToString());
            if (bytes.Length <= 1 )  // if there is only one byte, it is ASCII code
            {
                return false ;
            }
            else
            {
                byte byte1 = bytes[ 0 ];
                byte byte2 = bytes[ 1 ];
                if ( (byte1 >= 129 && byte1 <= 254 ) && ((byte2 >= 64 && byte2 <= 126 ) || (byte2 >= 161 && byte2 <= 254 )) )     // 判断是否是Big5编码
                {
                    return true ;
                }
                else
                {
                    return false ;
                }
            }
        }