How can I make a TextBox accepts only numeric values?

Question

I would like to know if there is a proper way for a textbox to accept only numbers.

For example, I want it to "stop" the user from filling it with "abcd1234" and only let him fill with "1234".

When you say you want the string to stop the user from entering non-numerical characters are you then talking about a TextBox ? If not please add more information about this. — MrApnea, Jun 14 '16 at 07:09
Possible duplicate of [How do I make a textbox that only accepts numbers?](http://stackoverflow.com/questions/463299/how-do-i-make-a-textbox-that-only-accepts-numbers) — Mathias R. Jessen, Jun 14 '16 at 07:13
first, what technology are you using? MVC, webpages, WPF, UWP, etc...? On the second hand, I'm guessing you map that to a property, so you should set that property to an `int`, and third, you can set your input to `type=number`(this works for web, not sure for WPF, UWP and others) and that will only allow numbers to be entered. — Spluf, Jun 14 '16 at 07:19
Why don't you use a numericUpDown? Is better if you just want there to be numbers — Aimnox, Jun 14 '16 at 08:47

score 17 · Accepted Answer · edited Dec 07 '17 at 14:02

17

I tried following code and worked fine for me. The textbox will allow user to enter numbers only.

private void txtbox1_KeyPress(object sender, KeyPressEventArgs e)
{
    if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar)) 
    {
        e.Handled = true;
    }
}

you can also try this

e.Handled = !(char.IsDigit(e.KeyChar));

edited Dec 07 '17 at 14:02

Molx

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answered Jun 14 '16 at 07:17

sowjanya attaluri

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Can user paste non-numeric with that? – ABuckau Jun 14 '16 at 07:22
No, Even though user try to enter alhabetics also,it won't allow. – sowjanya attaluri Jun 14 '16 at 07:23
How i "call" the method txtbox1_KeyPress with my textbox in the main method? – Mark Roll Jun 14 '16 at 07:25
2

Copy-paste .. Are you sure ? – ABuckau Jun 14 '16 at 07:25
1

To prevent copy/paste in TextBox using the keyboard set ShortcutsEnabled property to false. – Huzaifa Oct 31 '20 at 22:06

score 0 · Answer 2 · answered Jun 14 '16 at 07:15

You can evaluate the input using the following lines of code:

if (txtNumericBox.Text.All(char.IsDigit))
   // Proceed
else
   // Show error

If you define this as a string property with getter and setter then you can use like the following:

private string _MyNemericStringr;

public string MyNemericString
{
    get { return _MyNemericStringr; }
    set {
        if (value.All(char.IsDigit))
            _MyNemericStringr = value;
        else
            _MyNemericStringr = "0";
    }
}

In the second example, if you assign any non-digit value to the property then it will return the value as "0". otherwise it will process as usual.

score -1 · Answer 3 · answered Jul 29 '17 at 06:00

-1

you can try this simple code.

private void keypressbarcode(object sender, KeyPressEventArgs e)
{
        e.Handled = !(char.IsDigit(e.KeyChar) || e.KeyChar == (char)Keys.Back);
}

it only accept numeric values and Backspace

answered Jul 29 '17 at 06:00

Ramgy Borja

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How can I make a TextBox accepts only numeric values?

3 Answers3