Regular Expression which allows only one dot and digits WPF

Question

I have a textbox it should only allow only one dot and atleast one digit after the dot.

for eg: 1 and 1.2. If i enter 1. it should take 1.

33.0, 33, 55.23, 55.6,

i tried the following regex but it is not allowing dot.

It should allow only one dot in the textbox along with digits.

Can you please give more examples/elaborate on the matches you want have with your regex? — Kamuffel, May 27 '18 at 16:31
are you sure you need a regex for this? Might `Double.TryParse` fit your needs? — paul, May 27 '18 at 16:33
From your regular expression, it seems that you also want to allow spaces, no? — Zak, May 27 '18 at 17:00
My question is how restrict more than one dot in the textbox. that is not answered in that link. — Geeth, May 29 '18 at 09:10

Zak · Answer 1 · 2018-05-27T17:23:01.657

1

To ensure that your textbox can only contain a digit, optionally followed by a single period and 1 or more digits, use:

^\d+(\.\d+)?$

To also allow for an optional trailing or leading space, use:

^ ?\d+(\.\d+)? ?$

edited May 27 '18 at 17:23

answered May 27 '18 at 17:04

Zak

1

And what about `23.65` ? Add a quantifier after the first `\d`, like `\d+`. – Jan May 27 '18 at 17:12
Regex regex = new Regex("^\\d+(\\.\\d+)?$"); Its not allowing dot. – Geeth May 27 '18 at 17:40
private void _textBoxPreviewTextInput(object sender, System.Windows.Input.TextCompositionEventArgs e) { Regex regex = new Regex("^\\d+(\\.\\d+)?$"); e.Handled = !regex.IsMatch(e.Text); } – Geeth May 27 '18 at 17:42
@Geeth I'm sorry, but I can't test in wpf. The regex provided will match `1`, `1.2`,`33.0`, `33`, `55.23` and `55.6`. Do you need it to match just `.`? – Zak May 27 '18 at 19:30

1 Answers1