MVC 5 Data Annotation "Not Equal to Zero"

Question

Probably I am missing something, but having the model below

 public class MyModel
 {
     public double WhateverButNotZero { get; set; }
 }

is there any MVC built-in DataAnnotation to validate the number as "everything but zero"?

[Here](https://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations(v=vs.110).aspx) is the list of all DataAnnotation attributes available. Fast answer: no, there's none — Camilo Terevinto, Jul 21 '18 at 14:26
There is no built in `ValidationAttribute`, but you can use a [foolproof](https://archive.codeplex.com/?p=foolproof) `[NotEqualTo]` attribute, or if you want to learn to write your own conditional validation attributes, refer [The Complete Guide To Validation In ASP.NET MVC 3 - Part 2](https://www.devtrends.co.uk/blog/the-complete-guide-to-validation-in-asp.net-mvc-3-part-2) — , Jul 21 '18 at 22:27

SBFrancies · Answer 1 · 2018-07-21T15:04:07.080

5

Regex to the rescue:

public class MyModel
{
    [RegularExpression("(.*[1-9].*)|(.*[.].*[1-9].*)")]
    public double WhateverButNotZero { get; set; }
}

edited Jul 21 '18 at 15:04

answered Jul 21 '18 at 14:45

SBFrancies

3,987
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@SBFrancis, your answer works good, but it accepts letters in some cases Example: https://regex101.com/r/v4xi46/2/ – znn Jul 22 '18 at 16:42
2

But that shouldn't be possible with a double datatype. – SBFrancies Jul 22 '18 at 17:31

Felipe CS · Accepted Answer · 2023-06-12T20:29:27.753

There is no built-in validation for that specifically, but you can create a custom attribute for it if you don't want to use regex as mentioned in other answers.

Create a class that extends the ValidationAttribute class
Override the IsValid(object value) method
Inside your validation method, convert the object to int and check if it's equal zero

public class NotZeroAttribute : ValidationAttribute
{
    public override bool IsValid(object value) => (int)value != 0;
}

Then just use it on your class property like that:

public class MyModel
{
    [NotZero]
    public double WhateverButNotZero { get; set; }
}

Is not built-in, but surely the one I like the most. Functional, simple and clean. — znn, Nov 25 '22 at 10:55

Wei Lin · Answer 3 · 2018-07-21T15:01:46.970

1

try using regex annotation

public class MyModel
{
    [RegularExpression("^(?!0*(\.0+)?$)(\d+|\d*\.\d+)$", ErrorMessage = "Not Equal to Zero")]
    public double WhateverButNotZero { get; set; }
}

edited Jul 21 '18 at 15:01

answered Jul 21 '18 at 14:45

Wei Lin

3,591
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score 1 · Answer 4 · answered Jul 21 '18 at 15:21

1

You can use RegularExpression DataAnnotation attribute.

[RegularExpression(@"^\d*[1-9]\d*$")]
public double WhateverButNotZero { get; set; }

Hopefully, What is the regex for “Any positive integer, excluding 0” will be helpful to find out the regular expression as per your need.

answered Jul 21 '18 at 15:21

Parag

38
8

thanks for the answer, but what I'm looking for is "any number but zero". This means micro negatives or positives should be accepted, such as -0.0001, -0.0000000000001, 0.0123, etc – znn Jul 22 '18 at 16:25
In that case, I think "^[+-]?([0-9]\.\d+)|([1-9]\d*\.?\d*)$", this regular expression will be helpful, it will allow micro negatives or positives integers. – Parag Jul 22 '18 at 17:05

score 0 · Answer 5 · answered Feb 23 '23 at 14:42

0

Way I do it, and I think the easiest way

[Range(1, int.MaxValue, ErrorMessage = "Value must be greater than zero.")]

answered Feb 23 '23 at 14:42

Mal Clarke

147
2
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what about negative values? – znn Feb 23 '23 at 17:22
My solution obviously doesn't handle negative numbers. This works only for positive numbers – Mal Clarke Feb 23 '23 at 21:20
1

Indeed. But the question would like to achieve "any number but zero", which implies any possible number, from negative to positive, with or without decimal point. Your answer is good, but doesn't cover the actual question. – znn Feb 24 '23 at 12:02

MVC 5 Data Annotation "Not Equal to Zero"

5 Answers5