What are ASP.NET validation attributes and how do I use them?

What are ASP.NET validation attributes and how do I use them?

ASP.NET validation attributes are used to enforce validation rules on model properties in ASP.NET applications. They help ensure that user input meets specific criteria before being processed.

Can you give me some examples of these validation attributes?

Sure! Common validation attributes include [Required], [StringLength], [Range], and [EmailAddress]. For instance, [Required] ensures that a field is not empty.

How do I apply these attributes in my model class?

You can apply them directly above the properties in your model class. For example:

public class UserModel {
    [Required]
    public string Name { get; set; }

    [EmailAddress]
    public string Email { get; set; }
}

What happens if the validation fails?

If validation fails, the model state will be invalid, and you can return error messages to the user, prompting them to correct their input.