How can I use a MaskedTextBox to prevent the user from entering an invalid IP address? (I want it to behave just like the Windows one).
Much simpler than the other answers:
Use System.Net.IPAddress and System.Windows.Forms.MaskedTextBox
set the following properties of the MaskedTextBox:
MaskedTextBox.Mask = ###.###.###.###
MaskedTextBox.ValidatingType = typeof(System.Net.IPAddress);
whenever the text box is validating, event MaskedTextBox.TypeValidationCompleted is raised. The event arguments show the following:
Upon receipt of this event you can decide whether to use the value or notify the user what is wrong with the value.
Try this:
IPAddress ipAddress;
if (IPAddress.TryParse(maskedTextBoxY.Text, out ipAddress))
{
//valid ip
}
else
{
//is not valid ip
}
note: to use it, you need import the System.Net
namespace:
using System.Net;
It is better to use REGEX to validate user input. Here's an example:
string pattern = @"\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b";
string ip1 = "192.168.0.1";
string ip2 = "302.0.0.1";
Regex.IsMatch(ip1, pattern); // returns true
Regex.IsMatch(ip2, pattern); // returns false
Set the mask to: ###.###.###.###
Will display like this:
There is no complex solution for this question yet. I think @HaraldDutch answer is closest, but it is not prevet from input with space character. Using additional instruction:
IPAdressBox.ResetOnSpace = false;
generaly solved problem, but more complex is to implement own custom data typewith Parse method.
public class IPValidator
{
public static IPValidator Parse(string input)
{
Regex regexpr = new Regex(@" ");
Match match = regexpr.Match(input);
if (match.Success)
return new IPValidator();
else throw new ArgumentException(input);
}
}
Where regexpr is specific expresion to validate IP. After that it can be use as ValidatingType:
IPAdressBox.ValidatingType = typeof(IPValidator);
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