C#轉換字符串中漢字為其拼音縮寫

//將指定字符串中的漢字轉換為拼音縮寫，其中非漢字保留為原字符。
public string GetPinYin(string text)
{
char pinyin;
byte[] array;
System.Text.StringBuilder sb = new System.Text.StringBuilder(text.Length);
foreach(char c in text)
{
pinyin = c;
array = System.Text.Encoding.Default.GetBytes(new char[]{c});

if(array.Length == 2)
{
int i = array[0] * 0x100 + array[1];

if(i < 0xB0A1) pinyin = c; else
if(i < 0xB0C5) pinyin = 'a'; else
if(i < 0xB2C1) pinyin = 'b'; else
if(i < 0xB4EE) pinyin = 'c'; else
if(i < 0xB6EA) pinyin = 'd'; else
if(i < 0xB7A2) pinyin = 'e'; else
if(i < 0xB8C1) pinyin = 'f'; else
if(i < 0xB9FE) pinyin = 'g'; else
if(i < 0xBBF7) pinyin = 'h'; else
if(i < 0xBFA6) pinyin = 'g'; else
if(i < 0xC0AC) pinyin = 'k'; else
if(i < 0xC2E8) pinyin = 'l'; else
if(i < 0xC4C3) pinyin = 'm'; else
if(i < 0xC5B6) pinyin = 'n'; else
if(i < 0xC5BE) pinyin = 'o'; else
if(i < 0xC6DA) pinyin = 'p'; else
if(i < 0xC8BB) pinyin = 'q'; else
if(i < 0xC8F6) pinyin = 'r'; else
if(i < 0xCBFA) pinyin = 's'; else
if(i < 0xCDDA) pinyin = 't'; else
if(i < 0xCEF4) pinyin = 'w'; else
if(i < 0xD1B9) pinyin = 'x'; else
if(i < 0xD4D1) pinyin = 'y'; else
if(i < 0xD7FA) pinyin = 'z';
}

sb.Append(pinyin);
}

return sb.ToString();
}