Xpode.com        Click here to Print this article.

ASP.NET MVC interview questions: - What is data annotation validation in MVC? How to enable data annotation validation?

If you want to check string length, you can use “StringLength”.

[StringLength(160)]

public string FirstName { get; set; }


In case you want to use regular expression, you can use “RegularExpression” attribute.

[RegularExpression(@"[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}")]

public string Email { get; set; }


If you want to check whether the numbers are in range, you can use the “Range” attribute.

[Range(10,25)]

public int Age { get; set; }


Some time you would like to compare value of one field with other field, we can use the “Compare” attribute.

public string Password { get; set; }

[Compare("Password")]

public string ConfirmPass { get; set; }


In case you want to get a particular error message , you can use the “Errors” collection.

var ErrMessage = ModelState["Email"].Errors[0].ErrorMessage;


If you have created the model object yourself you can explicitly call “TryUpdateModel” in your controller to check if the object is valid or not.

TryUpdateModel(NewCustomer);


In case you want add errors in the controller you can use “AddModelError” function.


ModelState.AddModelError("FirstName", "This is my server-side error.");


Enable data annotation validation on client side : -

It’s a two-step process first reference the necessary jquery files.

<script src="<%= Url.Content("~/Scripts/jquery-1.5.1.js") %>" type="text/javascript"></script>

<script src="<%= Url.Content("~/Scripts/jquery.validate.js") %>" type="text/javascript"></script>

<script src="<%= Url.Content("~/Scripts/jquery.validate.unobtrusive.js") %>" type="text/javascript"></script>


Second step is to call “EnableClientValidation” method.

<% Html.EnableClientValidation(); %>


Also see the following ASP.NET MVC interview questions video on creating a simple customer model/class: -



http://
http://questpond.com/

Contributed by:
Shivprasad koirala Koirala
I am a Microsoft MVP for ASP/ASP.NET and currently a CEO of a small E-learning company in India. We are very much active in making training videos , writing books and corporate trainings. Do visit my site http://www.questpond.com for .NET, C# , design pattern , WCF , Silverlight , LINQ , ASP.NET , ADO.NET , Sharepoint , UML , SQL Server training and Interview questions and answers

Resourse address on xpode.com
http://www.xpode.com/Print.aspx?Articleid=721

Click here to go on website