ServiceNow Frequently Asked ASP.NET MVC Interview Questions Answers

What Is Razor View Engine?

Razor is the first major update to render HTML in ASP.Net MVC 3. Razor was designed specifically for view engine syntax. Main focus of this would be to simplify and code-focused templating for HTML generation.

Below is the sample of using Razor

@model ASP.Net MVCMusicStore.Models.Customer

@{ViewBag.Title = "Get Customers";}

< div class="cust">

@Model.CustomerName

What Is The Meaning Of Unobtrusive Javascript? Explain Us By Any Practical Example?

This is a general term that conveys a general philosophy, similar to the term REST (Representational State Transfer). Unobtrusive JavaScript doesn't inter mix JavaScript code in your page markup. Eg : Instead of using events like onclick and onsubmit, the unobtrusive JavaScript attaches to elements by their ID or class based on the HTML5 data- attributes.

Breifly Explain Us What Is Asp.net Mvc?

ASP.Net MVC is a pattern which is used to split the application's implementation logic into three components i.e. models, views, and controllers.

Tell Us Something About Model, View And Controllers In Asp.net Mvc?

Model : It is basically a business entity which is used to represent the application data.

Controller : The Request which is sent by the user always scatters through controller and it's responsibility is to redirect to the specific view using View () method.

View : it's the presentation layer of ASP.Net MVC.

Do You Know About The New Features In Asp.net Mvc 5?

Following are features added newly : Mobile templates Added ASP.NET Web API template for creating REST based services. Asynchronous controller task support. Bundling of the java scripts. Segregating the configs for ASP.Net MVC routing, Web API, Bundle etc.

What Is The Use Of View Model In Asp.net Mvc?

View Model is a plain class with properties, which is used to bind it to strongly typed view. View Model can have the validation rules defined for its properties using data annotations.

What You Mean By Routing In Asp.net Mvc?

Routing is a pattern matching mechanism of incoming requests to the URL patterns which are registered in route table. Class : "UrlRoutingModule" is used for the same process.

What Are Actions In Asp.net Mvc?

Actions are the methods in Controller class which is responsible for returning the view or json data. Action will mainly have return type : "ActionResult" and it will be invoked from method : "InvokeAction()" called by controller.

What Is Attribute Routing In Asp.net Mvc?

ASP.NET Web API supports this type routing. This is introduced in ASP.Net MVC5. In this type of routing, attributes are being used to define the routes. This type of routing gives more control over classic URI Routing.

Attribute Routing can be defined at controller level or at Action level like

[Route("{action = TestCategoryList}")] - Controller Level

[Route("customers/{TestCategoryId:int:min(10)}")] - Action Level
ServiceNow Frequently Asked ASP.NET MVC Interview Questions Answers
ServiceNow Frequently Asked ASP.NET MVC Interview Questions Answers

How To Enable Attribute Routing?

Just add @Model.CustomerName the method : "MapASP.Net MVCAttributeRoutes()" to enable attribute routing as shown below

public static void RegisterRoutes(RouteCollection routes)

    {

        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        //enabling attribute routing

        routes.MapASP.Net MVCAttributeRoutes();

        //convention-based routing

        routes.MapRoute

        (

            name: "Default",

            url: "{controller}/{action}/{id}",

            defaults: new { controller = "Customer", action = "GetCustomerList", id = UrlParameter.Optional }

        );

  }

What Are The Options Can Be Configured In Ajax Helpers?

Below are the options in AJAX helpers

Url : This is the request URL.

Confirm : This is used to specify the message which is to be displayed in confirm box.

OnBegin : Javascript method name to be given here and this will be called before the AJAX request.

OnComplete : Javascript method name to be given here and this will be called at the end of AJAX request.

OnSuccess - Javascript method name to be given here and this will be called when AJAX request is successful.

OnFailure - Javascript method name to be given here and this will be called when AJAX request is failed.

UpdateTargetId : Target element which is populated from the action returning HTML.

What Is Layout In Asp.net Mvc?

Layout pages are similar to master pages in traditional web forms. This is used to set the common look across multiple pages. In each child page we can find : /p>

@{

Layout = "~/Views/Shared/TestLayout1.cshtml";

} This indicates child page uses TestLayout page as it's master page.

Explain Json Binding?

JavaScript Object Notation (JSON) binding support started from ASP.Net MVC3 onwards via the new JsonValueProviderFactory, which allows the action methods to accept and model-bind data in JSON format. This is useful in Ajax scenarios like client templates and data binding that need to post data back to the server.

Explain Dependency Resolution?

Dependency Resolver again has been introduced in ASP.Net MVC3 and it is greatly simplified the use of dependency injection in your applications. This turn to be easier and useful for decoupling the application components and making them easier to test and more configurable.

Explain Bundle.config In Asp.net Mvc5?

"BundleConfig.cs" in ASP.Net MVC5 is used to register the bundles by the bundling and minification system. Many bundles are added by default including jQuery libraries like - jquery.validate, Modernizr, and default CSS references.

How Route Table Has Been Created In Asp.net Asp.net Mvc?

Method : "RegisterRoutes()" is used for registering the routes which will be added in "Application_Start()" method of global.asax file, which is fired when the application is loaded or started.

Which Are The Important Namespaces Used In Asp.net Mvc?

Below are the important namespaces used in ASP.Net MVC

System.Web.ASP.Net MVC
System.Web.ASP.Net MVC.Ajax
System.Web.ASP.Net MVC.Html
System.Web.ASP.Net MVC.Async

What Is Viewdata?

Viewdata contains the key, value pairs as dictionary and this is derived from class : "ViewDataDictionary". In action method we are setting the value for viewdata and in view the value will be fetched by typecasting.

What Is The Difference Between Viewbag And Viewdata In Asp.net Mvc?

ViewBag is a wrapper around ViewData, which allows to create dynamic properties. Advantage of viewbag over viewdata will be : In ViewBag no need to typecast the objects as in ViewData. ViewBag will take advantage of dynamic keyword which is introduced in version 4.0. But before using ViewBag we have to keep in mind that ViewBag is slower than ViewData.

Explain Tempdata In Asp.net Mvc?

TempData is again a key, value pair as ViewData. This is derived from "TempDataDictionary" class. TempData is used when the data is to be used in two consecutive requests, this could be between the actions or between the controllers. This requires typecasting in view.

What Are Html Helpers In Asp.net Mvc?

HTML Helpers are like controls in traditional web forms. But HTML helpers are more lightweight compared to web controls as it does not hold viewstate and events. HTML Helpers returns the HTML string which can be directly rendered to HTML page. Custom HTML Helpers also can be created by overriding "HtmlHelper" class.

How To Use Jquery Plugins In Asp.net Mvc Validation?

We can use dataannotations for validation in ASP.Net MVC. If we want to use validation during runtime using Jquery then we can use Jquery plugins for validation.

Eg

If validation is to be done on customer name textbox then we can do as

$('#CustomerName').rules("add", {

required: true,

minlength: 2,

messages: {

required: "Please enter name",

minlength: "Minimum length is 2"

}

});

How We Can Multiple Submit Buttons In Asp.net Mvc?

Below is the scenario and the solution to solve multiple submit buttons issue. Scenario

@using (Html.BeginForm("MyTestAction","MyTestController")

{

    <input type="submit" value="MySave" />

    <input type="submit" value="MyEdit" />

} Solution

Public ActionResult MyTestAction(string submit) //submit will have value either "MySave" or "MyEdit"

{

    // Write code here

}

What Are The Differences Between Partial View And Display Template And Edit Templates In Asp.net Mvc?

Display Templates : These are model centric. Meaning it depends on the properties of the view model used. It uses convention that will only display like divs or labels.

Edit Templates : These are also model centric but will have editable controls like Textboxes.

Partial View : These are view centric. These will differ from templates by the way they render the properties (Id's) Eg : CategoryViewModel has Product class property then it will be rendered as Model.Product.ProductName but in case of templates if we CategoryViewModel has List then @Html.DisplayFor(m => m.Products) works and it renders the template for each item of this list.

Can I Set The Unlimited Length For "maxjsonlength" Property In Config?

No. We can't set unlimited length for property maxJsonLength. Default value is - 102400 and maximum value what we can set would be : 2147483644.

Can I Use Razor Code In Javascript In Asp.net Mvc?

Yes. We can use the razor code in javascript in cshtml by using <text> element.

< script type="text/javascript">

@foreach (var item in Model) {

< text >

//javascript goes here which uses the server values

< text >

}

< script>

How Can I Return String Result From Action In Asp.net Mvc?

Below is the code snippet to return string from action method

public ActionResult TestAction() {

return Content("Hello Test !!");

}

What Are Ajax Helpers In Asp.net Mvc?

AJAX Helpers are used to create AJAX enabled elements like as Ajax enabled forms and links which performs the request asynchronously and these are extension methods of AJAXHelper class which exists in namespace - System.Web.ASP.Net MVC.

Explain Sections Is Asp.net Mvc?

Section are the part of HTML which is to be rendered in layout page. In Layout page we will use the below syntax for rendering the HTML

@RenderSection("TestSection") And in child pages we are defining these sections as shown below

@section TestSection{

<h1>Test Content<h1>

} If any child page does not have this section defined then error will be thrown so to avoid that we can render the HTML like this

@RenderSection("TestSection", required: false)

How To Change The Action Name In Asp.net Mvc?

"ActionName" attribute can be used for changing the action name.

Below is the sample code snippet to demonstrate more

[ActionName("TestActionNew")]

public ActionResult TestAction()

    {

       return View();

    }

So in the above code snippet "TestAction" is the original action name and in "ActionName" attribute, name - "TestActionNew" is given. So the caller of this action method will use the name "TestActionNew" to call this action.

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