字符和ACSII码

byte[] Sn = new byte[8];
Array.Copy(MainBuf, 4, Sn, 0, 8);
string strSn = " ";
for (int isn = 0; isn < 8; isn++)
{
strSn += Sn[isn];
}
其中Sn[1] = 65;strSn显示出来的值也是65.怎么才能变成A；

[解决办法]
Encoding.Default.GetString(Sn);
[解决办法]
string strSn = " ";
for (int isn = 0; isn < 8; isn++)
{
strSn += ((char)Sn[isn]).ToString();
}
[解决办法]
strSn += ((char)Sn[isn]).tostring();
[解决办法]
(char)((char)Sn[1]).ToString();