采用对应的区位的方法，但有些汉字不在这个范围里，大家试一下
public string hz2py(string hz) //获得汉字的区位码
{
byte[] sarr = System.Text.Encoding.Default.GetBytes(hz);
int len = sarr.Length;
if (len>1)
{
byte[] array = new byte[2];
array = System.Text.Encoding.Default.GetBytes(hz);
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(hz);
// int i1 = (short)(array[0] - '\0');
// int i2 = (short)(array[1] - '\0');
// int t1 = Convert.ToInt32(i1,16);
// int t2 = Convert.ToInt32(i2,16);
int tmp=i1*256+i2;
string getpychar="*";//找不到拼音码的用*补位
if(tmp>=45217&&tmp<=45252){getpychar= "A";}
else if(tmp>=45253&&tmp<=45760){getpychar= "B";}
else if(tmp>=47761&&tmp<=46317){getpychar= "C";}
else if(tmp>=46318&&tmp<=46825){getpychar= "D";}
else if(tmp>=46826&&tmp<=47009){getpychar= "E";}
else if(tmp>=47010&&tmp<=47296){getpychar= "F";}
else if(tmp>=47297&&tmp<=47613){getpychar= "G";}
else if(tmp>=47614&&tmp<=48118){getpychar= "H";}
else if(tmp>=48119&&tmp<=49061){getpychar= "J";}
else if(tmp>=49062&&tmp<=49323){getpychar= "K";}
else if(tmp>=49324&&tmp<=49895){getpychar= "L";}
else if(tmp>=49896&&tmp<=50370){getpychar= "M";}
else if(tmp>=50371&&tmp<=50613){getpychar= "N";}
else if(tmp>=50614&&tmp<=50621){getpychar= "O";}
else if(tmp>=50622&&tmp<=50905){getpychar= "P";}
else if(tmp>=50906&&tmp<=51386){getpychar= "Q";}
else if(tmp>=51387&&tmp<=51445){getpychar= "R";}
else if(tmp>=51446&&tmp<=52217){getpychar= "S";}
else if(tmp>=52218&&tmp<=52697){getpychar= "T";}
else if(tmp>=52698&&tmp<=52979){getpychar= "W";}
else if(tmp>=52980&&tmp<=53640){getpychar= "X";}
else if(tmp>=53689&&tmp<=54480){getpychar= "Y";}
else if(tmp>=54481&&tmp<=55289){getpychar= "Z";}
return getpychar;
}
else
{
return hz;
}
}
public string transpy(string strhz) //把汉字字符串转换成拼音码
{
string strtemp="";
int strlen=strhz.Length;
for (int i=0;i<=strlen-1;i++)
{
strtemp+=hz2py(strhz.Substring(i,1));
}
return strtemp;
}