In this article I will explain with an example, how to perform Numeric TextBox Validation i.e. allow only Number validation on Client Side using Data Annotation and jQuery in ASP.Net MVC.
The Numeric TextBox Validation i.e. allow only Number (Digits) validation and it will be performed on Client Side using Model class and Data Annotation attributes in ASP.Net MVC.
Note: For beginners in ASP.Net MVC, please refer my article ASP.Net MVC Hello World Tutorial with Sample Program example.
 
 

Model

The following Model class consists of one property Age. The property is decorated with the following Data Annotation attributes for performing validations.
1. Required Data Annotation attribute.
2. RegularExpression Data Annotation attribute.
Note: The Data Annotations attributes can be used with the Entity Data Model (EDM), LINQ to SQL, and other data models.
 
The RegularExpression Data Annotation attribute accepts the Regular Expression as first parameter.
The Regular Expression will allow only Numbers (Digits).
The Required Data Annotation and the RegularExpression Data Annotation attributes have been specified with a property ErrorMessage with a string value. As the name suggests, this string value will be displayed to the user when the respective validation fails.
Valid example: 30
using System.ComponentModel.DataAnnotations;
 
namespace Numeric_Validation_MVC.Models
{
    public class PersonModel
    {
        [Display(Name = "Age:")]
        [Required(ErrorMessage = "Age is required.")]
        [RegularExpression("^[0-9]*$", ErrorMessage = "Only Numbers allowed.")]
        public int Age { get; set; }
    }
}
 
 

Controller

The Controller consists of following Action methods.

Action method for handling GET operation

Inside this Action method, simply the View is returned.
 

Action method for handling POST operation

This Action method handles the POST operation and when the form is submitted, the object of the PersonModel class is sent to this method.
The state of the submitted Model is checked using ModelState.IsValid property.
Note: ModelState.IsValid property is an inbuilt property which verifies two things:
         1. Whether the Form values are bound to the Model.
         2. All the validations specified inside Model class using Data annotations have been passed.
 
public class HomeController : Controller
{
    // Get: Home
    public ActionResult Index()
    {
        return View();
    }
 
    [HttpPost]
    public ActionResult Index(PersonModel person)
    {
        if (ModelState.IsValid)
        {
            // Validation Success.
        }
 
        return View();
    }
}
 
 

View

HTML Markup

Inside the View, in the very first line the PersonModel class is declared as Model for the View.
The View consists of an HTML Form which has been created using the Html.BeginForm method with the following parameters.
ActionName – Name of the Action. In this case the name is Validate.
ControllerName – Name of the Controller. In this case the name is Home.
FormMethod – It specifies the Form Method i.e. GET or POST. In this case it will be set to POST.
The Form consists of a Label, an HTML INPUT TextBox, a SPAN element and a Submit Button.
 

Implementing Validation

The Form consists of the following three HTML Helper functions:-
1. Html.LabelFor – Displaying the Model property name.
1. Html.TextBoxFor – Creating TextBox for the Model property.
2. Html.ValidationSummary – Displaying the Validation message for the properties when the validation fails.
 

Submitting the Form

When the Submit Button is clicked, the Form gets submitted and the Age value is sent to the Controller.
 

Enabling Client-Side validations

By default, the validations using Data Annotations and Model class is performed on Server Side.
In order to enable Client-Side validations, you will need to inherit the following script files.
1. jquery.min.js
2. jquery.validate.js
3. jquery.validate.unobtrusive.js
Once, the above files are inherited automatically, the Client-Side validations using Data Annotations is enabled.
@model Numeric_Validation_MVC.Models.PersonModel
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    @using (Html.BeginForm("Index", "Home", FormMethod.Post))
    {
        <table>
            <tr>
                <td>@Html.LabelFor(m => m.Age)</td>
                <td>@Html.TextBoxFor(m => m.Age)</td>
                <td>@Html.ValidationMessageFor(m => m.Age, "", new { @class = "error" })</td>
            </tr>
            <tr>
                <td></td>
                <td><input type="submit" value="Submit" /></td>
                <td></td>
            </tr>
        </table>
    }
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.19.3/jquery.validate.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validation-unobtrusive/3.2.12/jquery.validate.unobtrusive.js"></script>
</body>
</html>
 
 

Screenshot

ASP.Net MVC: Numeric TextBox Validation (Numbers) using Data Annotations
 
 

Downloads

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