Create a Custom Control that can only take PrintRanges (numbers, comma and range)

Question

1.00/5 (2 votes)

See more:

Newbie here!!

I am creating a custom textbox control based on Forms.TextBox. It should

a) only take individual values separated by commas (1,2,3)
b) a valid range separated by numbers (5-9 but not 9-5)
c) should not accept comma in the first character
d) autocorrect comma in the last character

I am overriding the KeyPress propoerty as follows but unable to get access to the text value entered so far to build the validations above. Please help.

Thanks,

VB

Protected Overrides Sub OnKeyPress(ByVal e As System.Windows.Forms.KeyPressEventArgs)
        MyBase.OnKeyPress(e)


    If (Asc(e.KeyChar) >= 48 And Asc(e.KeyChar) <= 57) Or Asc(e.KeyChar) = 8 Then
                    e.Handled = False

        ElseIf e.KeyChar = "," Then


    ElseIf e.KeyChar = "-"

        'Struggling with the Code for validation
    Else

        'Struggling with the Code for validation
    End if

End Sub

Posted 12-Oct-14 4:05am

Member 11127394

Updated 12-Oct-14 6:13am

v2

Add a Solution

Comments

Maciej Los 12-Oct-14 11:15am

What's the question?

Member 11127394 12-Oct-14 12:12pm

Can you help me with the code to build validations? The logic:

a) It can't start with a commma or -
b) Cannot have 2 consecutive commas
c) Cannot have a '-' after a comma
d) Should validate a range (should not allow 9-5)

I need to somehow get access to the text entered so far...dont know how

Thanks

3 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2014-10-12T06:29:00

Just one idea: try to use the different class: System.Windows.Forms.MaskedTextBox, or derive from it:
http://msdn.microsoft.com/en-us/library/system.windows.forms.maskedtextbox%28v=vs.110%29.aspx[^].

Your post is not really a question, this is a request to do part of your work, some UI design. To make your posts more useful, you could rather try to do a design and ask more specific questions when you face some problems, when some behaviors show some flaws, something like that.

—SA

CHill60 · Answer 2 · 2014-10-12T06:45:00

Further to Solution 1 (recommended), assuming you stick with your current approach then TextBox1.Text is the contents of the text box.

However, I think you should use Validating event in preference to the OnKeyPress event.

You can still use OnKeyPress to ensure that only 0-9, comma and backspace are accepted e.g.

VB

If (Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57) And Not (New Integer() {8, Asc("-"), Asc(",")}.Contains(Asc(e.KeyChar))) Then
    e.Handled = True

Your attempt was close but you need to set e.Handled = True to ignore the key

Maciej Los · Answer 3 · 2014-10-12T08:57:00

Solution 3

Another way is to create Regex validator ;)

Please, see: Validation with Regular Expressions Made Simple[^]

Posted 12-Oct-14 8:57am

Maciej Los

Comments

CHill60 12-Oct-14 15:05pm

Of course! 5.

Maciej Los 12-Oct-14 15:21pm

Thank you, Caroline ;)

Sergey Alexandrovich Kryukov 12-Oct-14 16:07pm

I hope it would be possible to avoid validation (to keep input also valid), but validation is just another aspect unrelated to filtering input.
—SA

Maciej Los 12-Oct-14 16:25pm

To be honest, i'm not sure i understand you correctly... Why, in your opinion, validation is unrelated to filtering input? In which aspect?

Sergey Alexandrovich Kryukov 12-Oct-14 16:34pm

I just reviewed the question. Yes, it could be just validation, up-voted.
The point is: 1) filtering is useful and comes first; 2) if filtering overly complex, could confuse the users; 3) validation may or may not be needed; it's best when it's not needed, but it's better then complicated confusing filtering.
—SA

Maciej Los 12-Oct-14 17:17pm

Thank you, Sergey. As you know, your opinion is important to me. I agree with your opinion. Now, it's more 'readable' to me ;)