String转成Unicode

public string String2Unicode(string source)
{
byte[] bytes = Encoding.Unicode.GetBytes(source);
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < bytes.Length; i += 2)
{
stringBuilder.AppendFormat("\\u{0}{1}", bytes[i + 1].ToString("x").PadLeft(2, '0'), bytes[i].ToString("x").PadLeft(2, '0'));
}
return stringBuilder.ToString();
}