CSharp Validate Internet URL Function With Regular Expression

Posted by Hoan Huynh in CSharp

February 5, 2012

1. C# validate URL function

public bool validate_url(string internet_url)
{
    Regex reg = new Regex(@"http(s)?://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?");
 
    return reg.IsMatch(internet_url);
}

2. Put them all together with example in ASP.net page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text.RegularExpressions;
 
public partial class csharp_validate_url : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string url = "http://4rapiddev.com";
 
        if (validate_url(url))
        {
            Response.Write(url + " is a VALID internet URL");
        }
        else
        {
            Response.Write(url + " is NOT a valid internet URL");
        }
        //Output: http://4rapiddev.com is a VALID internet URL 
    }
 
    public bool validate_url(string internet_url)
    {
        Regex reg = new Regex(@"http(s)?://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?");
 
        return reg.IsMatch(internet_url);
    }
}

Note: you need to declare System.Text.RegularExpressions namespace in order for Regex class works properly.

Download source code above.

Tagged: Regex regular expression RegularExpressions