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;   
                  }