byte[] array = new byte[2];

array = System.Text.Encoding.Default.GetBytes("啊");

int i1 = (short)(array[0] - '\0');

int i2 = (short)(array[1] - '\0');

//unicode解码方式下的汉字码

array = System.Text.Encoding.Unicode.GetBytes("啊");

i1 = (short)(array[0] - '\0');

i2 = (short)(array[1] - '\0');

//unicode反解码为汉字

string str = "4a55";

string s1 = str.Substring(0,2);

string s2 = str.Substring(2,2);

int t1 = Convert.ToInt32(s1,16);

int t2 = Convert.ToInt32(s2,16);

array[0] = (byte)t1;

array[1] = (byte)t2;

string s = System.Text.Encoding.Unicode.GetString(array);

//default方式反解码为汉字

array[0] = (byte)196;

array[1] = (byte)207;

s = System.Text.Encoding.Default.GetString(array);

//取字符串长度

s = "iam方枪枪";

int len = s.Length;//will output as 6

byte[] sarr = System.Text.Encoding.Default.GetBytes(s);

len = sarr.Length;//will output as 3+3*2=9

//字符串相加

System.Text.StringBuilder sb = new System.Text.StringBuilder("");

sb.Append("i ");

sb.Append("am ");

sb.Append("方枪枪");