C# - Hexcode eines Strings ausgeben

public string StringToHexString (string str) 
{     
  StringBuilder sb = new StringBuilder(); 
  foreach (char c in str) 
  { 
    sb.Append("0x"); 
    sb.Append(Convert.ToString(c,16)); 
    sb.Append(" "); 
  } 
  return sb.ToString(); 
}