Gartner ASP.NET MVC Interview Questions Answers

Gartner Most Frequently Asked ASP.NET MVC Interview Questions Answers

Explain how you can send the result back in JSON format in MVC?

In order to send the result back in JSON format in MVC, you can use “JSONRESULT” class.

List out the types of result in MVC?

In MVC, there are twelve types of results in MVC where “ActionResult” class is the main class while the 11 are their sub-types

ViewResult
PartialViewResult
EmptyResult
RedirectResult
RedirectToRouteResult
JsonResult
JavaScriptResult
ContentResult
FileContentResult
FileStreamResult
FilePathResult

Mention what is the importance of NonActionAttribute?

All public methods of a controller class are treated as the action method if you want to prevent this default method then you have to assign the public method with NonActionAttribute.

Mention what is the use of the default route {resource}.axd/{*pathinfo} ?

This default route prevents request for a web resource file such as Webresource.axd or ScriptResource.axd from being passed to the controller.

Mention the order of the filters that get executed, if the multiple filters are implemented?

The filter order would be like

Authorization filters
Action filters
Response filters
Exception filters

Explain how routing is done in MVC pattern?

There is a group of routes called the RouteCollection, which consists of registered routes in the application.  The RegisterRoutes method records the routes in this collection.  A route defines a URL pattern and a handler to use if the request matches the pattern. The first parameter to the MapRoute method is the name of the route. The second parameter will be the pattern to which the URL matches.  The third parameter might be the default values for the placeholders if they are not determined.

Explain using hyperlink how you can navigate from one view to other view?

By using “ActionLink” method as shown in the below code. The below code will make a simple URL which help to navigate to the “Home” controller and invoke the “GotoHome” action.

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<%= Html.ActionLink(“Home”, “Gotohome”) %>

Gartner Most Frequently Asked ASP.NET MVC Interview Questions Answers

Mention what filters are executed in the end?

In the end “Exception Filters” are executed.

Mention what are the file extensions for razor views?

For razor views the file extensions are

.cshtml: If C# is the programming language
.vbhtml: If VB is the programming language

Mention what are the two ways for adding constraints to a route?

Two methods for adding constraints to route is

Using regular expressions
Using an object that implements IRouteConstraint interface

Mention how can maintain session in MVC?

Session can be maintained in MVC by three ways tempdata, viewdata, and viewbag.

Mention what is the difference between Temp data, View, and View Bag?

Temp data: It helps to maintain data when you shift from one controller to other controller.
View data: It helps to maintain data when you move from controller to view
View Bag: It’s a dynamic wrapper around view data

What is partial view in MVC?

Partial view in MVC renders a portion of view content. It is helpful in reducing code duplication. In simple terms, partial view allows to render a view within the parent view.

Explain how you can implement Ajax in MVC?

In Ajax, MVC can be implemented in two ways

Ajax libraries
Jquery.

What is ASP.NET MVC?

ASP.NET MVC is a web application Framework. It is light weight and highly testable Framework. MVC separates application into three components — Model, View and Controller.

What is Razor View Engine?

Razor is the first major update to render HTML in 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 MvcMusicStore.Models.Customer
@{ViewBag.Title = “Get Customers”;}
<div class=”cust”> <h3><em>@Model.CustomerName</em> </h3>

What you mean by Routing in 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 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 MVC?

ASP.NET Web API supports this type routing. This is introduced in 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

How to enable Attribute Routing?

Just add the method — “MapMvcAttributeRoutes()” to enable attribute routing as shown below

public static void RegistearRoutes(RouteCollection routes)

{

routes.IgnoareRoute(“{resource}.axd/{*pathInfo}”);

//enabling attribute routing

routes.MapMvcAttributeRoutes();

//convention-based routing

routes.MapRoute

(

name: “Default”,

url: “{controller}/{action}/{id}”,

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

);

}

Can you explain Model, Controller and View in MVC?

Model — It’s a business entity and it is used to represent the application data.

Controller — Request 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 MVC.