Summary of C#'s method of judging character encoding (six methods)

protected bool  IsChineseLetter(string input,int index)
{
    int code = 0;
    int chfrom = Convert.ToInt32("4e00", 16);  //Convert range (0x4e00～0x9ff) to int (chfrom～chend)    int chend = Convert.ToInt32("9fff", 16);
    if (input != "")
    {
       code = Char.ConvertToUtf32(input, index);  //Get the character unicode encoding at the specified index in the string input      if (code >= chfrom && code <= chend)
      {
         return true;   //Return true when the code is in Chinese range       }
      else
      {
         return false ;  //Return false when the code is not in Chinese range       }
     }
     return false;
}

public bool IsChina(string CString)
{
   bool BoolValue = false;
   for (int i = 0; i < ; i++)
   {
     if (Convert.ToInt32(((i, 1))) < Convert.ToInt32((128)))
     {
       BoolValue = false;
     }
     else
     {
       return BoolValue = true;
     }
   }
   return BoolValue;
}

/// <summary>
/// Determine whether the sentence contains Chinese: Ningxia University Zhang Dong./// </summary>
/// <param >Strings</param>public bool WordsIScn(string words)
{
  string TmmP;
  for (int i = 0; i &lt; ; i++)
  {
    TmmP = (i, 1);
    byte[] sarr = ("gb2312").GetBytes(TmmP);
    if ( == 2)
    {
      return true;
    }
  }
  return false;
}

for (int i=0; i<; i++)
{
Regex rx = new Regex("^[/u4e00-/u9fa5]$");
if ((s[i]))
// yeselse
// no}

unicodeencoding unicodeencoding = new unicodeencoding();
byte [] unicodebytearray = ( inputstring );
for( int i = 0; i < ; i++ )
{
i++;
//If it is a Chinese character, the high position will not be 0if ( unicodebytearray[i] != 0 )
{
}
……

/// <summary>
/// Given a string, determine whether it contains only Chinese characters/// </summary>
/// <param name="testStr"></param>
/// <returns></returns>
public bool IsOnlyContainsChinese(string testStr)
{
  char[] words = ();
  foreach (char word in words)
  {
    if ( IsGBCode(()) || IsGBKCode(()) ) // it is a GB2312 or GBK chinese word
    {
      continue;
    }
    else
    {
      return false;
    }
  }
  return true;
}
/// <summary>
/// Determine whether a word is a Chinese character encoded by GB2312/// </summary>
/// <param name="word"></param>
/// <returns></returns>
private bool IsGBCode(string word)
{
  byte[] bytes = ("GB2312").GetBytes(word);
  if ( <= 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)  //Judge whether it is GB2312    {
      return true;
    }
    else
    {
      return false;
    }
  }
}
/// <summary>
/// Determine whether a word is a GBK-encoded Chinese character/// </summary>
/// <param name="word"></param>
/// <returns></returns>
private bool IsGBKCode(string word)
{
  byte[] bytes = ("GBK").GetBytes(());
  if ( <= 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)   //Judge whether it is GBK encoding    {
      return true;
    }
    else
    {
      return false;
    }
  }
}
/// <summary>
/// Determine whether a word is a Big5 coded Chinese character/// </summary>
/// <param name="word"></param>
/// <returns></returns>
private bool IsBig5Code(string word)
{
  byte[] bytes = ("Big5").GetBytes(());
  if ( <= 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)) )   //Judge whether it is Big5 encoding    {
      return true;
    }
    else
    {
      return false;
    }
  }
}