Comments by Member 10686581 (Top 14 by date)

Yeah I've done that now here is the code I have used:

private void btnCheck_Click(object sender, EventArgs e)
{

String AllowedChars = ("^(?!PAN)(?!SOS)[A-Z]{3}\\d{4}$");
if (Regex.IsMatch(txtIdentification.Text, AllowedChars))
{
MessageBox.Show("Valid");
}
else
{
MessageBox.Show("Invalid");
}

}

When I enter a PAN or SOS I need it to give me a different output, how do I do this?

Thank you this looks like what I'm looking for but I need the code for windows form.

I have a textbox and a button, once the button is clicked it needs to check what the user has inputted in the textbox, how would I go about adapting your code in this way? I would need to display the valid and invalid outputs in either another textbox or as an error message.

It's not me whos idea it is to let the user input an incorrect format lol, it just needs to be able to display a message saying invalid format.. I tried to create a regular expression for the format of LLLNNNN using a program but it just gives me: [a-zA-Z]{3}[0-9]{4}

Once I get the expression could I just use it like this:

private void textBox5_Validating(object sender, CancelEventArgs e)
{
String AllowedChars = [a-zA-Z]{3}[0-9]{4};
if (Regex.IsMatch(textBox5.Text, AllowedChars))
{
MessageBox.Show("Valid");
}
else
{
MessageBox.Show("Invalid");
}
}

I don't think masking will work because when the user inputs the ID, I need to display whether it is valid or invalid in another text box.. if I used masking it would let the user only enter in a valid format so it leaves no room to enter an invalid one.

Just looked at the regular expressions, it's so confusing!