C#判断字符编码的方法总结(六种方法)

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;
}

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;
}

/// <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;
}

for (int i=0; i<s.length; i++)
{
Regex rx = new Regex("^[/u4e00-/u9fa5]$");
if (rx.IsMatch(s[i]))
// 是
else
// 否
}

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 )
{
}
……

/// <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;
    }
  }
}