Validate input in textbox

Try something like this:

      Private Function ValidateTextBox(ByVal txt As String) As Boolean
        Try
            If txt = String.Empty Then
                Return False
            Else
                Dim str() As String = txt.Split(";"c)
                For Each line As String In str
                    If line.Length <> 7 Or Not IsNumeric(line) Then
                        Return False
                    End If
                Next
                Return True
            End If
        Catch ex As Exception
            Return False
        End Try
 
    End Function
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If ValidateTextBox(Me.TextBox1.Text) Then
            Debug.WriteLine("Valid information!")
        Else
            Debug.WriteLine("Wrong information!")
        End If
    End Sub

Select allOpen in new window

Well the code I post it it works this way:

Valid inputs:
1234567
1234567;1234567
1234567;1234567;1234567

Invalid inputs;
1234567;
1234567;Addaaa;
123;
etc

I think it's not practical to force the user to add always the last ";" ... but may be required :)

Sorry, but I forgot to mention that the 7 digits MUST be numerical...

Have you tried my function ?

@jpaulino:
No , I have'nt, but Regular Expressions seem the logical way to do this....

That's your decision ...

@fernandosoto

Hi,
this works fine, but only for 1 '7d+;"
Entering 1234567;7654321;8523695;456852 returns an error. And that is what I was looking for

Well my solution works fine but that's you call!

I only don't understand why you want to use regex ... because it's slower or because it sounds better.

because I had made up my mind to use the REGEX solution for its clean and ' much fewer lines to code ' way of coding a complex thing.Compare your solution (which works fine, I do not argue that) with the REGEX solution.
Why would a REGEX be slower ????
Apart from that...code just needs to work, not ' sound ' better.......

Of course that in this simple validation the speed is not a point but just for your information I have made a test with only 10000 repetitions (on a loop and using a stopwatch) using both methods. Here's the results:

(values in miliseconds)
Code: 243
Code: 244
Code: 243
Code: 241
Code: 242
Code: 243

Regex:417
Regex:425
Regex:419
Regex:421
Regex:416
Regex:421

I also use regex but for this I didn't found really necessary. But this is just my opinion :)

Good luck

Hi JamesBrian;

To have either a semicolon or no semicolon at the end of the list of digits change the regex pattern from this,
 "^(\d{7};)+$", to this, "^(\d{7}?)+$".

Fernando