public static string Bit7Extract(byte[] data)
{
BitExtract extract = new BitExtract(data);
StringBuilder result = new StringBuilder();
while (true)
{
List <bool> bits = extract.GetBits(7);
if (bits.Count < 7)
{
break;
}
char ch = (char)BitExtract.ToByte(bits, 7);
// 正好末尾是 7 bits 1111111，需要丢弃
// TODO: 注意测试这种情况
if (extract.Count == 0 && ch == 0x7f)
{
break;
}
result.Append(ch);
}
return(result.ToString());
}
public static string Bit6Extract(byte[] data)
{
BitExtract extract = new BitExtract(data);
StringBuilder result = new StringBuilder();
while (true)
{
List <bool> bits = extract.GetBits(6);
if (bits.Count < 6)
{
break;
}
char ch = (char)BitExtract.ToByte(bits, 6);
// 如果正好末尾是 6 bits 100000，需丢弃
// 注意测试这种情形, 应正确丢弃
if (extract.Count == 0 && ch == 0x20)
{
break;
}
if ((ch & 0x20) == 0x00)
{
ch = (char)(ch | 0x40);
}
result.Append(ch);
}
return(result.ToString());
}
public static string Bit5Extract(byte[] data)
{
BitExtract extract = new BitExtract(data);
StringBuilder result = new StringBuilder();
while (true)
{
List <bool> bits = extract.GetBits(5);
if (bits.Count < 5)
{
break;
}
if (BitExtract.IsZero(bits))
{
break;
}
char ch = (char)(BitExtract.ToByte(bits, 5) | 0x40);
result.Append(ch);
}
return(result.ToString());
}
public static string IsilExtract(byte[] data)
{
char save_charset = 'u';
char current_charset = 'u';
BitExtract extract = new BitExtract(data);
StringBuilder result = new StringBuilder();
while (true)
{
int bit_count = char.ToLower(current_charset) == 'd' ? 4 : 5;
string bits = extract.GetBitsString(bit_count);
if (bits.Length < bit_count)
{
break;
}
// 切换命令
if (current_charset == 'u' || current_charset == 'U')
{
// 小写锁定
if (bits == "11100")
{
current_charset = 'l';
continue;
}
// 小写 shift
if (bits == "11101")
{
save_charset = current_charset;
current_charset = 'L';
continue;
}
// 数字锁定
if (bits == "11110")
{
current_charset = 'd';
continue;
}
// 数字 shift
if (bits == "11111")
{
save_charset = current_charset;
current_charset = 'D';
continue;
}
}
// 切换命令
if (current_charset == 'l' || current_charset == 'L')
{
// 大写锁定
if (bits == "11100")
{
current_charset = 'u';
continue;
}
// 大写 shift
if (bits == "11101")
{
save_charset = current_charset;
current_charset = 'U';
continue;
}
// 数字锁定
if (bits == "11110")
{
current_charset = 'd';
continue;
}
// 数字 shift
if (bits == "11111")
{
save_charset = current_charset;
current_charset = 'D';
continue;
}
}
// 切换命令
if (current_charset == 'd' || current_charset == 'D')
{
// 大写锁定
if (bits == "1100")
{
current_charset = 'u';
continue;
}
// 大写 shift
if (bits == "1101")
{
save_charset = current_charset;
current_charset = 'U';
continue;
}
// 小写锁定
if (bits == "1110")
{
current_charset = 'l';
continue;
}
// 小写 shift
if (bits == "1111")
{
save_charset = current_charset;
current_charset = 'L';
continue;
}
}
char ch = (char)BitExtract.ToByte(bits, bit_count);
if (current_charset == 'u' || current_charset == 'U')
{
if (bits == "00000")
{
result.Append('-');
}
else if (bits == "11011")
{
result.Append(':');
}
else if (ch >= 0x01 && ch <= 0x1a)
{
result.Append((char)(ch - 1 + 'A'));
}
else
{
throw new Exception("error 1");
}
if (current_charset == 'U')
{
current_charset = save_charset;
}
continue;
}
if (current_charset == 'l' || current_charset == 'L')
{
if (bits == "00000")
{
result.Append('-');
}
else if (bits == "11011")
{
result.Append('/');
}
else if (ch >= 0x01 && ch <= 0x1a)
{
result.Append((char)(ch - 1 + 'a'));
}
else
{
throw new Exception("error 2");
}
if (current_charset == 'L')
{
current_charset = save_charset;
}
continue;
}
if (current_charset == 'd' || current_charset == 'D')
{
if (bits == "1010")
{
result.Append('-');
}
else if (bits == "1011")
{
result.Append(':');
}
else if (ch >= 0 && ch <= 0x09)
{
result.Append((char)('0' + ch));
continue;
}
else
{
throw new Exception("error 3");
}
if (current_charset == 'D')
{
current_charset = save_charset;
}
continue;
}
break;
}
return(result.ToString());
}