How to prevent user to put any special character in the textbox using textchanged event C#?

Question

1.00/5 (1 vote)

See more:

this is apply on web application i don't want to use javascript

What I have tried:

protected void TextBox1_TextChanged(object sender, EventArgs e)
{

string text = ((TextBox)sender).Text;
var regex = new Regex(@"[^a-zA-Z0-9\s]");
if (!regex.IsMatch(text.ToString()))
{
return false;
}
}

Posted 27-Apr-18 3:07am

Member 13801308

Updated 27-Apr-18 3:25am

Add a Solution

Comments

F-ES Sitecore 27-Apr-18 8:17am

You can't stop that using the server-side events as those events only fire after the user has updated the textbox and the form has been submitted. You could strip the unwanted text in that event if you wanted to, but you can't stop it. You'll need to use javascript to do that.

1 solution

Add a Solution

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

OriginalGriff · Accepted Answer · 2018-04-27T03:26:00

Solution 1

Don't even try to do this server side - not only would it mean a round trip to the server every time the user types a key, which would really mess up typing speeds, it's a spectacularly bad way to think, even if you could do it, which you can't.

You need to do this in Javascript: How to restrict special characters and spaces in textbox via javascript?[^]

Posted 27-Apr-18 3:26am

OriginalGriff

Comments

F-ES Sitecore 27-Apr-18 9:09am

That event is only called (assuming autopostback) when the textbox loses focus, not on each keypress.

How to prevent user to put any special character in the textbox using textchanged event C#?

1 solution

Solution 1

Add your solution here

Preview 0

How to prevent user to put any special character in the textbox using textchanged event C#?

1 solution

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us