Regular expression for URL

Question

I have written regex to validate URL which could be either like

• example.com

• www.example.com

• http://www.example.com

Answer 1

This works for me:

string pattern = @"^(ht|f)tp(s?)\:\/\/[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(:(0-9)*)*(\/?)([a-zA-Z0-9\-\.\?\,\'\/\\\+&%\$#_]*)?$";

Regex regex = new Regex(pattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);

string url= txtAddressBar.Text.Trim();

if(regex.IsMatch(url)
{
  //do something
}