How to write the follow simple sha1Hex() in C#(.net) ?

Question

Howtowritethefollowsimplesha1Hex(sbyte[]data,stringkey)inC#(.net)?下面是Java的代码，c#要怎么写这个简单的算法，要带key的。
publicstaticstringsha1Hex(sbyte[]data,stringkey)
{
sbyte[]keyBytes=key.GetBytes();
SecretKeySpecsigningKey=newSecretKeySpec(keyBytes,"HmacSHA1");
Macmac;
StringBuildersb=newStringBuilder();
try
{
mac=Mac.getInstance("HmacSHA1");
mac.init(signingKey);
sbyte[]rawHmac=mac.doFinal(data);
foreach(sbytebinrawHmac)
{
sb.Append(byteToHexString(b));
}
}
catch(Exception)
{
}
returnsb.ToString();
}