how can validate special characters in textbox c#.net

Bagesh kumar singh

12y39.5kVisual Basic .NET

hi ,

I am writing this code to validate special characters

Regex r = newRegex(@"[~`!@#$%^&*()-+=|\{}':;.,<>/?]");

if (r.IsMatch(txtJobPackName.Text))

{

MessageBox.Show("special characters are not allowed !!!");

TextBox1.Text ="";

}

but my problem is that i am not able to validate some charater( []-_ " ). can you please give the sulotation. its urgent.

5 Replies

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Vulpes12y ago
Accepted answer
One other thing I've just noticed is that your original expression is not validating the backslash character. It needs to be escaped by doubling it:

Regex r = new Regex(@"[~`!@#$%^&*()+=|\\{}':;.,<>/?[\]""_-]");
Vulpes11y ago
Do you mean that the textbox should contain at least one character but no character should be a special character?
Naga Harsha11y ago
hi i used your snippet but it gets null when i enter special charecters.. please validate me that textbox should not be empty.. its urgent.. thank you
Naeem Khan12y ago
hello friend,
I m given you code for all validation like address, name , price etc..

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace demo
{
class Validation
{
public static void price_validation(KeyPressEventArgs e)
{
int num = e.KeyChar;

if (e.KeyChar == '.' || num == 8)
{
e.Handled = false;
}
else if (!char.IsDigit(e.KeyChar))
{
e.Handled = true;
}
}

public static void numeric_validation(KeyPressEventArgs e)
{
int num = e.KeyChar;

if (num == 8)
{
e.Handled = false;
}
else if (!char.IsDigit(e.KeyChar))
{
e.Handled = true;
}
}
public static void talepehone_validation(KeyPressEventArgs e)
{
int num = e.KeyChar;

if (e.KeyChar == ',' || e.KeyChar == ' ' || num == 8)
{
e.Handled = false;
}
else if (!char.IsDigit(e.KeyChar))
{
e.Handled = true;
}
}
public static void name_validation(KeyPressEventArgs e)
{
int num = e.KeyChar;
if (e.KeyChar == '.' || e.KeyChar == ' ' || e.KeyChar == '&' || num == 8 || char.IsDigit(e.KeyChar) || e.KeyChar == '-')
{
e.Handled = false;
}
else if (!char.IsLetter(e.KeyChar))
{
e.Handled = true;
}
}
public static void address_validation(KeyPressEventArgs e)
{
int num = e.KeyChar;
if (e.KeyChar == ',' || e.KeyChar == '-' || e.KeyChar == '/' || e.KeyChar == ' ' || num == 8 || char.IsDigit(e.KeyChar) || num == 13)
{
e.Handled = false;
}
else if (!char.IsLetter(e.KeyChar))
{
e.Handled = true;
}
}

public static void vision_validation(KeyPressEventArgs e)
{
int num = e.KeyChar;
if (e.KeyChar == ',' || e.KeyChar == '-' || e.KeyChar == '/' || e.KeyChar == ' ' ||e.KeyChar == '.' || num == 8 || char.IsDigit(e.KeyChar))
{
e.Handled = false;
}
else if (!char.IsLetter(e.KeyChar))
{
e.Handled = true;
}
}
}
}

just implement this code..
hope it would be help full for you..if not then reply me will give you other solution
Vulpes12y ago
Try:

Regex r = new Regex(@"[~`!@#$%^&*()+=|\{}':;.,<>/?[\]""_-]");

Note that:

1. ']' needs to be escaped by prefixing it with '\' so that it's not treated as the end of the set.

2. It's generally best to place hyphen '-' at the end of the set so it's not treated as the range operator.

3. The double quote symbol '"' needs to be doubled as it's within a verbatim string.