Check the scanned input value is only numbers in C#

Question

else if (vReadData.Length==14 && vReadData Is Numeric)
{
    if (txtIPLoad_MHEBarcode1.Text == "")
{
    txtIPLoad_MISBarcode1.Text = vReadData;
    txtIPLoad_MHEBarcode1.Focus();
}
else
{
    txtIPLoad_MISBarcode2.Text = vReadData;
    txtIPLoad_MHEBarcode2.Focus();
}
    mMessage("Scan", "Please scan the MHE Barcode!");
    return;
}

This is my code for validating a Textbox. I check the condition that the length should be 14 chars. I must also check that the input which comes in variable vReadData must be numeric (only numbers). Please help me solve this.

I have tried using

 else if (Int64.TryParse(vReadData, out num))

but this is not helping me.

Is `IsNumeric` not working? Looks like your missing or have too many curly brackets. Might be the issue. — Hemi81, Feb 15 '17 at 10:36

Dmitry Bychenko · Accepted Answer · 2017-02-15T11:05:13.480

1

Are you looking for a regular expression?

 else if (Regex.IsMatch(vReadData, @"^[0-9]{14}$")) {
   // vReadData is a string of exactly 14 digits [0..9] 
 }

Explanation: we have to match two conditions

The string should be exactly 14 characters long
It should be a valid (non-negative) number (I doubt if any negative bar code exits)

After combining both conditions into one we can say that we're looking for a string which consist of 14 digits [0-9] (please notice, that we want [0-9] not \d, since \d in .Net means any digit, including, say Persian ones)

Tests:

string vReadData = @"B2MX15235687CC";
// vReadData = @"12345678901234";

if (Regex.IsMatch(vReadData, @"^[0-9]{14}$"))
  Console.Write("Valid");
else
  Console.Write("InValid");

Outcome:

InValid

If you uncomment the line you'll get

Valid

edited Feb 15 '17 at 11:05

answered Feb 15 '17 at 10:24

Dmitry Bychenko

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no sir i want to check if input value is only numbers – Santhosh Raja Feb 15 '17 at 10:26
@Santhosh Raja: I'm sorry, don't follow you; could you provide some *examples* (both *positive* and *negative*)? For instance is `123,456,789,99` an accepted input? It contains numbers and has a length of 14 chars in total. Is `12345678901234` valid input? What about `00000000000000` (14 zeros)? Do you accept `3.14159265352` floating point number? Scientific notation? `1.23456789e123`? Negative `-1234567890123` – Dmitry Bychenko Feb 15 '17 at 10:29
eg "B2MX" this should not satisfy the condition "12345" this value should be accepted – Santhosh Raja Feb 15 '17 at 10:31
@Santhosh Raja: I see, and my *current* regular expression rules this input out. – Dmitry Bychenko Feb 15 '17 at 10:32
If the input is numbers ,condition must satisfy – Santhosh Raja Feb 15 '17 at 10:33
@Santhosh Raja: are you looking for non-negative *numbers* which are **from** `1` **up to** `14` digits? Can the numbers start from zero? E.g. `00123`? Can the number be *negative* `-123`? – Dmitry Bychenko Feb 15 '17 at 10:34
the length of input must be 14 digits, for that i used vReadData.Length==14 now one more condition is it must be numeric eg (12345678901234) – Santhosh Raja Feb 15 '17 at 10:38
It should satisfy both these condition – Santhosh Raja Feb 15 '17 at 10:39
@Santhosh Raja: I've combined *both* condition into *one* (providing that the number should not be negative): you're looking for string which contains exactly 14 digits – Dmitry Bychenko Feb 15 '17 at 10:40
will this work for "B2MX15235687CC" this kind of data it should not accept – Santhosh Raja Feb 15 '17 at 10:44
@Santhosh Raja: and my current regular expression returns `false` for this input as expected – Dmitry Bychenko Feb 15 '17 at 10:51
thanks sir it worked!!!!! @dmitry – Santhosh Raja Feb 15 '17 at 11:01

Check the scanned input value is only numbers in C#

1 Answers1