public bool isUtf8(byte[] rawText)         {             bool result = true;             if (rawText == null)             {                 return !result;             }             int pos = 0;             while (pos < rawText.Length && result)             {                 if ((rawText[pos] & 0x7F) == rawText[pos])                 {                     pos++;                 }                 else                 {                     int bitLen = 7;                     while (((rawText[pos] >> bitLen) & 0x01) == 1 && bitLen > 0)                     {                         bitLen--;                     }                     int byteCount = 7 - bitLen;                     if (byteCount > 1 && byteCount < 7)                     {                         for (int i = 1; i < byteCount; ++i)                         {                             if (pos + i >= rawText.Length || (rawText[pos + i] & 0xBF) != rawText[pos + i])                             {                                 result = false;                                 break;                             }                         }                         pos += byteCount;                     }                     else                     {                         result = false;                     }                 }             }             return result;         }