How do I validate an input requiring two hex characters?

Question

I want to validate a string value from textbox.

Validation requirements are:

Exactly 2 characters
Hex characters only

How can I do this?

are you wanting to convert a string value to hex or trim an existing hex value..? — MethodMan, Dec 20 '11 at 22:05
Not conversion.I want to do validaiton to getting to characher which in range 00-FF — mixo_17, Dec 20 '11 at 22:06
I can get two charcater it is okey ,but the range is problem — mixo_17, Dec 20 '11 at 22:08
UInt unsigned it's your best bet would be to parse out each char within the string... — MethodMan, Dec 20 '11 at 22:11

score 3 · Accepted Answer · edited Dec 20 '11 at 23:02

3

Use a Regex validator control with the expression: ^[0-9A-F]{2}$

edited Dec 20 '11 at 23:02

Naftuli Kay

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answered Dec 20 '11 at 22:08

Sam

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2

by the way, if you want to allow lowercase, you'll need to account for that as well: ^[0-9A-Fa-f]{2}$ – Sam Dec 20 '11 at 22:09

score 1 · Answer 2 · answered Dec 13 '12 at 08:02

1

             String^ temp = "012345679abcdefABCDEF";
             if (temp->IndexOf(e->KeyChar) == -1)
             {
                 e->Handled = true;
             }

use this for hex character control

answered Dec 13 '12 at 08:02

Muzaffer DILEK

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score 1 · Answer 3 · edited Dec 20 '11 at 22:54

1

You could use a regular expression, something like:

^([0-9A-F]{2})$

edited Dec 20 '11 at 22:54

Glory Raj

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answered Dec 20 '11 at 22:08

JeffCren

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score 0 · Answer 4 · answered Dec 20 '11 at 22:13

//Use this method and before calling it ..pass or parse out the string.Substring(0,2)

public string ConvertToHex(string asciiString)
{ 
    var newasciiString = Substring(asciiString,0,2);
    string hex = "";
    foreach (char c in newasciiString)
    {
        int tmp = c;
        hex += String.Format("{0:x2}", (uint)System.Convert.ToUInt32(tmp.ToString()));
    }
    return hex;
}

How do I validate an input requiring two hex characters?

4 Answers4