The windows form text field should accept only the URL name

Question

Hey. I need to verify that the text field should only accept URL names. Can someone tell me please. I would be very grateful.

Answer 1

I don’t think there is a built-in method or class that you can use to validate a string as a legal url. But you can use a regular expression, something like ["^ a-zA-Z0-9 -._"] +. ([A-zA-Z] [a-zA-Z]) If you use the code from Ranhiru, you will not get it correctly, for example, bild.de and s.int, which are valid URLs.

Answer 2

URL-, ? , , , , , URL- .

, URL. , . , "ping", "http://".

, a) -, b) .

Answer 3

:

    public void Test()
    {
        Uri result = UrlIsValid("www.google.com");
        if (result == null)
        {
            //Invalid Url format
        }
        else
        {
            if (UrlExists(result))
            {
                //Url is valid and exists
            }
            else
            {
                //Url is valid but the site doesn't exist
            }
        }
        Console.ReadLine();
    }

    private static Uri UrlIsValid(string testUrl)
    {
        try
        {
            if (!(testUrl.StartsWith(@"http://") || testUrl.StartsWith(@"http://")))
            {
                testUrl = @"http://" + testUrl;
            }
            return new Uri(testUrl);
        }
        catch (UriFormatException)
        {
            return null;
        }   
    }

    private static bool UrlExists(Uri validUri)
    {
        try
        {   
            WebRequest.Create(validUri).GetResponse();
            return true;
        }

        catch (WebException)
        {
            return false;
        }
    }

, , UrlExists.

Answer 4

:)

using System.Text.RegularExpressions;

private bool validateURL()
        {

            Regex urlCheck = new Regex("^[a-zA-Z0-9\-\.]+\.(com|org|net|mil|edu|COM|ORG|NET|MIL|EDU)$");

            if (urlCheck.IsMatch(txtUrlAddress.Text))
                return true;
            else
            {
                MessageBox.Show("The url address you have entered is incorrect!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); 
                return false;

            }




        }

   if (validateURL() == true)
          //Do something
    else
          //Do something else

Check out more url regular expressions here http://www.regexlib.com/Search.aspx?k=url&c=-1&m=5&ps=20

Answer 5

Much simpler:

    /// <summary>
    /// Validates that the URL text can be parsed.
    /// </summary>
    /// <remarks>
    /// Does not validate that it actually points to anything useful.
    /// </remarks>
    /// <param name="urlText">The URL text.</param>
    /// <returns></returns>
    private bool ValidateURL(string urlText)
    {
        bool result;

        try
        {
            Uri check = new Uri(urlText);
            result = true;
        }
        catch (UriFormatException)
        {
            result = false;
        }

        return result;
    }

Answer 6

his work is for me

private bool ValidateURL (string urlText) {bool result;

    try
    {
        Uri check = new Uri(urlText);
        result = true;
    }
    catch (UriFormatException)
    {
        result = false;
    }

    return result;
}