In this article I will explain with an example, how to implement dd/MM/yyyy Date format validation for TextBox in ASP.Net Core MVC.
The RegularExpression Data Annotation will be used along with RegularExpression (Regex) for enforcing dd/MM/yyyy Date format validation for TextBox 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.
 
 

Regular Expression (Regex) to validate Date Format

Regular Expression (Regex)

(((0|1)[0-9]|2[0-9]|3[0-1])\/(0[1-9]|1[0-2])\/((19|20)\d\d))$
 
 

Model

The following Model class consists of one property BirthDate to which the following validation Data Annotation attributes have been applied.
1. Required Data Annotation attribute.
2. RegularExpression Data Annotation attribute.
The Regular Expression Data Annotation attribute accepts the Regular Expression as first parameter. The Regular Expression will allow only dd/MM/yyyy date format.
The Required Data Annotation and the Regular Expression Data Annotation attributes have been specified with a property Error Message with a string value. As the name suggests, this string value will be displayed to the user when the respective validation fails.
public class PersonModel
{
    [Display(Name = "Birth Date")]
    [Required(ErrorMessage = "Birth Date is required.")]
    [RegularExpression(@"(((0|1)[0-9]|2[0-9]|3[0-1])\/(0[1-9]|1[0-2])\/((19|20)\d\d))$", ErrorMessage = "Invalid date format.")]
    public string BirthDate { 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.
public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        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 Index.
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.
Inside the View, the following three HTML Helper functions are used:-
1. Html.LabelFor – Displaying the Model property name.
2. Html.TextBoxFor – Creating a TextBox for the Model property.
3. Html.ValidationMessageFor – Displaying the Validation message for the property.
The Form also consists of a Submit button.
 
In order to enable Client-Side validations, you will need to inherit the following script files.
1. jquery.js
2. jquery.validate.js
3. jquery.validate.unobtrusive.js
 

Submitting the Form

When Submit button is clicked, the Form gets submitted.
@model Date_ddMMyyyy_validation_MVC.Models.PersonModel
 
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width"/>
    <title>Index</title>
    <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/1.21.0/jquery.validate.min.js;></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validation-unobtrusive/4.0.0/jquery.validate.unobtrusive.min.js;></script>
</head>
<body>
    @using (@Html.BeginForm("Index", "Home", FormMethod.Post))
    {
        @Html.LabelFor(m => m.BirthDate)
        @Html.TextBoxFor(m => m.BirthDate)
        @Html.ValidationMessageFor(m => m.BirthDate, "", new { @class = "error" })
        <hr />
        <input type="submit" value="Submit" />
    }
</body>
</html>
 
 

Enabling Client-Side validations

By default, the validations performed using Data Annotations and Model class is performed on Server Side.
Then, adding the ClientValidationEnabled and UnobtrusiveJavaScriptEnabled keys in the AppSettings section in the Web.Config file.
<appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="ClientValidationEnabled"value="true" />
    <add key="UnobtrusiveJavaScriptEnabled"value="true" />
</appSettings>
 
 

Screenshot

Implement dd/MM/yyyy Date format validations in ASP.Net MVC
 
 

Downloads

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