DataAnnotation

DataAnnotation is used for validation. It supports following propperties

• Required – Indicates that the property is a required field
• DisplayName – Defines the text we want used on form fields and validation messages
• StringLength – Defines a maximum length for a string field
• Range – Gives a maximum and minimum value for a numeric field
• Bind – Lists fields to exclude or include when binding parameter or form values to model properties
• ScaffoldColumn – Allows hiding fields from editor forms

Example

 class MainClass

    {

        public void CopyDataByMapper()

        {

            Person objPerson = new Person();           

            objPerson.FirstName = "";

            objPerson.LastName = "Ahmad";

            var context = new ValidationContext(objPerson,null,null);

            var result = new List();

            bool IsValid = Validator.TryValidateObject(objPerson,context,result,true);

            Console.WriteLine(IsValid);

            foreach (var item in result)

            {

                Console.WriteLine(item.ErrorMessage);

            }

            Console.ReadKey();

        }

    }

    class Person

    {

        [Required(ErrorMessage = "FirstName is required")]

        [StringLength(20)]

        public String FirstName { get; set; }

        public String LastName { get; set; }

    }