C#

string Encode(string input)
{
  StringBuilder sr = new StringBuilder();
  //go through each letter in your string
  foreach(char character in input)
  {
    int value = (int)character;
    sr.Append('%');
    //ToString("X") formats a decimal as hexadecimal
    sr.Append(value.ToString("X"));
  }  
  return sr.ToString();
}

private string CovertToHex(string text)
{
    string hex = "";
    foreach (char c in text)
    {
        int tmp = c;
        hex += String.Format("{0:x2}", (uint)System.Convert.ToUInt32(tmp.ToString()));
    }
    return hex;
}

Fayu wrote:

snipplet below will help anyone who was trying to do the same.

private string UrlEncodeAllCharacters(string text) {
   StringBuilder builder = new StringBuilder(text.Length * 3);
   foreach (char c in text) {
      builder.Append('%').Append(((int)c).ToString("x2"));
   }
   return builder.ToString();
}