I’d like to restrict my form input from entering non-english characters. For example, all Chinese, Japanese, Cyrllic, but also single characters like: à, â, ù, û, ü, ô, î, ê. Would this be possible? Do I have to set up a locale on my MVC application or rather just do a regex textbox validation? Just a side note, I want to be able to enter numbers and other characters. I only want this to exclude letters.
Please advice, thank you
Answers:
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Method 1
For this you have to use Unicode character properties and blocks. Each Unicode code points has assigned some properties, e.g. this point is a Letter. Blocks are code point ranges.
For more details, see:
- regular-expressions.info for some general information about Unicode code points, character properties, scripts and blocks
- MSDN for the supported properties and blocks in .net
Those Unicode Properties and blocks are written p{Name}, where “Name” is the name of the property or block.
When it is an uppercase “P” like this P{Name}, then it is the negation of the property/block, i.e. it matches anything else.
There are e.g. some properties (only a short excerpt):
- L ==> All letter characters.
- Lu ==> Letter, Uppercase
- Ll ==> Letter, Lowercase
- N ==> All numbers. This includes the Nd, Nl, and No categories.
- Pc ==> Punctuation, Connector
- P ==> All punctuation characters. This includes the Pc, Pd, Ps, Pe, Pi, Pf, and Po categories.
- Sm ==> Symbol, Math
There are e.g. some blocks (only a short excerpt):
- 0000 – 007F ==> IsBasicLatin
- 0400 – 04FF ==> IsCyrillic
- 1000 – 109F ==> IsMyanmar
What I used in the solution:
P{L} is a character property that is matching any character that is not a letter (“L” for Letter)
p{IsBasicLatin} is a Unicode block that matches the code points 0000 – 007F
So your regex would be:
^[P{L}p{IsBasicLatin}]+$
In plain words:
This matches a string from the start to the end (^ and $), When there are (at least one) only non letters or characters from the ASCII table (doce points 0000 – 007F)
A short c# test method:
string[] myStrings = { "Foobar",
"<a href="https://getridbug.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="8fc9e0e0cfedeefd">[email protected]</a>!"§$%&/()",
"Föobar",
"fóÓè"
};
Regex reg = new Regex(@"^[P{L}p{IsBasicLatin}]+$");
foreach (string str in myStrings) {
Match result = reg.Match(str);
if (result.Success)
Console.Out.WriteLine("matched ==> " + str);
else
Console.Out.WriteLine("failed ==> " + str);
}
Console.ReadLine();
Prints:
matched ==> Foobar
matched ==> [email protected]!Ӥ$%&/()
failed ==> Föobar
failed ==> fóÓè
Method 2
You can use a Regular Expression attribute on your ViewModel to restrict that
public class MyViewModel
{
[System.ComponentModel.DataAnnotations.RegularExpression("[a-zA-Z]+")]
public string MyEntry
{
get;
set;
}
}
Method 3
You can use regex [x00-x80]+ or [u0000-u0080]+. Haven’t tested but think it should work in C# also.
Adapted from: Regular expression to match non-English characters?
You can use regex validation for textbox and validate on the server also.
Method 4
May be this one help You:=
private void Validate(TextBox textBox1)
{
Regex rx = new Regex("[^A-Z|^a-z|^ |^t]");
if (rx.IsMatch(textBoxControl.Text))
throw new Exception("Your error message");
}
Usefull Link:-
Method 5
this might help, not efficient way but simple non-reg validation
foreach (char c in inputTextField)
{
if ((int)(c) > 127)
{
// expection or your logic whatever you want to return
}
}
All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0