[ Log On ]
< <


Posted By: P.K.R
5/16/2013 12:00:00 AM
language: MVC



MVC means ?


MVC stands for Model View Controller.
It divides an application into 3 component roles which is based on a framework methodology.
These component roles are discussed briefly as follows:

i) Models : These component roles are used to maintain the state which is persisted inside the Database.

Example: we might have a Product class that is used to represent order data from the Products table inside SQL.

ii) Views : These component roles are used to display the user interface of the application, where this UI is created off of the model data.

Example: we might create an Product “Edit” view that surfaces textboxes, dropdowns and checkboxes based on the current state of a Product object.

iii) Controllers : These component roles are used for various purposes like handling end user interaction, manipulating the model, and ultimately choosing a view to render to display UI.


In a MVC application, the views are used only for displaying the information whereas the controllers are used for handling and responding to user input and interaction.


Which assembly is used to define the MVC framework and Why ?


The MVC framework is defined through System.Web.Mvc assembly.
This is because this is the only assembly which contains classes and interfaces that support the ASP.NET Model View Controller (MVC) framework for creating Web applications.


How can we plug an ASP.NET MVC into an existing ASP.NET application ?


We can combine ASP.NET MVC into an existing ASP.NET application by following the below procedure:

First of all, you have to add a reference to the following three assemblies to your existing ASP.NET application:

i) System.Web.Routing
ii) System.Web.Abstractions
iii) System.Web.Mvc

The ASP.NET MVC folder should be created after adding these assembly references.
Add the folder Controllers, Views, and Views | Shared to your existing ASP.NET application.
And then you have to do the necessary changes in web.config file.
For this you can refer to the below link:


What are the advantages of using mvc ?


The main advantages of using mvc are as follows:

i) One of the main advantage is that it will be easier to manage the complexity as the application is divided into model,view and controller.
ii) It gives us the full control over the behavior of an application as it does not use view state or server-based forms.
iii) It provides better support for test-driven development (TDD).
iv) You can design the application with a rich routing infrastructure as it uses a Front Controller pattern that processes Web application requests through a single controller.


Explain about Razor View Engine ?


This Razor View engine is a part of new rendering framework for ASP.NET web pages.
ASP.NET rendering engine uses opening and closing brackets to denote code (<% %>), whereas Razor allows a cleaner, implied syntax for determining where code blocks start and end.


In the classic renderer in ASP.NET:


<% foreach (var userTicket in Model)

  { %>

    <li><%: userTicket.Value %></li>

<%  } %>



By using Razor:


@foreach (var userTicket in Model)







Does the unit testing of an MVC application is possible without running controllers in an ASP.NET process ?


In an MVC application, all the features are based on interface. So, it is easy to unit test a MVC application.
And it is to note that, in MVC application there is no need of running the controllers for unit testing.


Which namespace is used for ASP.NET MVC ?


System.Web.Mvc namespace contains all the interfaces and classes which supports ASP.NET MVC framework for creating web applications.


Can we share a view across multiple controllers ?


Yes, It is possible to share a view across multiple controllers by putting a view into the shared folder.
By doing like this, you can automatically make the view available across multiple controllers.


What is the use of a controller in an MVC applicatio ?


A controller will decide what to do and what to display in the view. It works as follows:

i) A request will be received by the controller
ii) Basing on the request parameters, it will decide the requested activities
iii) Basing on the request parameters, it will delegates the tasks to be performed
iv) Then it will delegate the next view to be shown


Mention some of the return types of a controller action method ?


An action method is used to return an instance of any class which is derived from ActionResult class.
Some of the return types of a controller action method are:
i) ViewResult : It is used to return a webpage from an action method
ii) PartialViewResult : It is used to send a section of a view to be rendered inside another view.
iii) JavaScriptResult : It is used to return JavaScript code which will be executed in the user’s browser.
iv) RedirectResult : Based on a URL, It is used to redirect to another controller and action method.
v) ContentResult : It is an HTTP content type may be of text/plain. It is used to return a custom content type as a result of the action method.
vi) JsonResult : It is used to return a message which is formatted as JSON.
vii) FileResult : It is used to send binary output as the response.
viii) EmptyResult : It returns nothing as the result.


Explain about 'page lifecycle' of ASP.NET MVC ?


The page lifecycle of an ASP.NET MVC page is explained as follows:

i) App Initialisation
In this stage, the aplication starts up by running Global.asax’s Application_Start() method.
In this method, you can add Route objects to the static RouteTable.Routes collection.
If you’re implementing a custom IControllerFactory, you can set this as the active controller factory by assigning it to the System.Web.Mvc.ControllerFactory.Instance property.

ii) Routing
Routing is a stand-alone component that matches incoming requests to IHttpHandlers by URL pattern.
MvcHandler is, itself, an IHttpHandler, which acts as a kind of proxy to other IHttpHandlers configured in the Routes table.

iii) Instantiate and Execute Controller
At this stage, the active IControllerFactory supplies an IController instance.

iv) Locate and invoke controller action
At this stage, the controller invokes its relevant action method, which after further processing, calls RenderView().

v) Instantiate and render view
At this stage, the IViewFactory supplies an IView, which pushes response data to the IHttpResponse object.


Explain about NonActionAttribute ?


It is already known that all the public methods of a controller class are basically treated as action methods.
If you dont want this default behaviour, then you can change the public method with NonActionAttribute. Then, the default behaviour changes.


Explain about the formation of Router Table in ASP.NET MVC ?


The Router Table is formed by following the below procedure:

In the begining stage, when the ASP.NET application starts, the method known as Application_Start() method is called.
The Application_Start() will then calls RegisterRoutes() method.
This RegisterRoutes() method will create the Router table.



In an MVC application, what are the segments of the default route ?


There are 3 segments of the default route in an MVC application.They are:

The 1st segment is the Controller Name.
Example: search

The 2nd segment is the Action Method Name.
Example: label

The 3rd segment is the Parameter passed to the Action method.
Example: Parameter Id - MVC


What are the settings to be done for the Routing to work properly in an MVC application ?


The settings must be done in 2 places for the routing to work properly.They are:

i) Web.Config File : In the web.config file, the ASP.NET routing has to be enabled.
ii) Global.asax File : The Route table is created in the application Start event handler, of the Global.asax file.


How to avoid XSS Vulnerabilities in ASP.NET MVC ?


To avoid xss vulnerabilities, you have to use the syntax as '<%: %>' in ASP.NET MVC instead of using the syntax as '<%= %>' in .net framework 4.0.
This is because it does the HTML encoding.


<input type="text" value="<%: value%>" />


Explain the advantages of using routing in ASP.NET MVC ?


Without using Routing in an ASP.NET MVC application, the incoming browser request should be mapped to a physical file.The thing is that if the file is not there, then you will get a page not found error.
By using Routing, it will make use of URLs where there is no need of mapping to specific files in a web site.
This is because, for the URL, there is no need to map to a file, you can use URLs that are descriptive of the user's action and therefore are more easily understood by users.


What are the things that are required to specify a route ?


There are 3 things that are required to specify a route.

i) URL Pattern : You can pass the variable data to the request handler without using a query string. This is done by including placeholders in a URL pattern.
ii) Handler : This handler can be a physical file of 2 types such as a .aspx file or a controller class.
iii) Name for the Route : This name is an optional thing.


Is the route {controller}{action}/{id} a valid route definition or not and why ?


{controller}{action}/{id} is not a valid route definition.
The reason is that, it has no literal value or delimiter between the placeholders.
If there is no literal, the routing cannot determine where to seperate the value for the controller placceholder from the value for the action placeholder.


Explain about default route, {resource}.axd/{*pathInfo} ...


With the help of this default route {resource}.axd/{*pathInfo}, you can prevent requests for the web resources files such as WebResource.axd or ScriptResource.axd from being passed to a controller.



Explain the difference between adding routes, to a web application and to an mvc application ?


We use MapPageRoute() method of a RouteCollection class for adding routes to a webforms application, whereas MapRoute() method is used to add routes to an MVC application.


Is there any way to handle variable number of segments in a route definition ?


You can handle variable number of segments in a route definition by using a route with a catch-all parameter.


Here * reffers to catch-all parameter.


How do you add constraints to a route ?


There are 2 ways for adding constraints to a route. They are:
i) By using Regular Expressions and
ii) By using an object which implements IRouteConstraint interface.


Explain with examples for scenarios when routing is not applied ?


Below are the 2 scenarios where routing is not applied.

i) A Physical File is Found that Matches the URL Pattern - This default behaviour can be overriden by setting the RouteExistingFiles property of the RouteCollection object to true.
ii) Routing Is Explicitly Disabled for a URL Pattern - By using the RouteCollection.Ignore() method, you can prevent routing from handling certain requests.


Explain the usage of action filters in an MVC application ?


Action filter in an mvc application is used to perform some additional processing, such as providing extra data to the action method, inspecting the return value, or canceling execution of the action method.
Action filter is an attribute that implements the abstract FilterAttribute class.


In an MVC application, which filter executes first and which is the last ?


As there are different types of filters in an MVC application, the Authorization filter is the one which executes first and Exeption filters executes in the end.


Difference between Viewbag and Viewdata in ASP.NET MVC ?


Both are used to pass the data from controllers to views.
The difference between Viewbag and Viewdata in ASP.NET MVC is explained below:

View Data:
In this, objects are accessible using strings as keys.


In the Controller:
public ActionResult Index()
var softwareDevelopers = new List<string>
"Brendan Enrick",
"Kevin Kuebler",
"Todd Ropog"
ViewData["softwareDevelopers"] = softwareDevelopers;
return View();

In the View:
@foreach (var developer in (List<string>)ViewData["softwareDevelopers"])

An important note is that when we go to use out object on the view that we have to cast it since the ViewData is storing everything as object.

View Bag:
It will allow the objectto dynamically have the properties add to it.


In the Controller:
public ActionResult Index()
var softwareDevelopers = new List<string>
"Brendan Enrick",
"Kevin Kuebler",
"Todd Ropog"
ViewBag.softwareDevelopers = softwareDevelopers;
return View();

In the View:
@foreach (var developer in ViewBag.softwareDevelopers)

An important point to note is that there is no need to cast our object when using the ViewBag. This is because the dynamic we used lets us know the type.


What are the file extensions for razor views ?


There are two types of file extensions for razor views.
They are:

i) .cshtml : This file extension is used, when the programming language is a C#.
ii) .vbhtml : This file extension is used, when the programming language is a VB.



How can you specify comments using razor syntax ?


In razor syntax, we use the below shown symbols for specifying comments.

i) For indicating the begining of a comment, we use @* syntax.
ii) For indicating the end of a comment, we use *@ syntax.


Explain the usage of validation helpers in ASP.NET MVC ?


In ASP.NET MVC, validation helpers are used to show the validation error messages in a view.
The Html.ValidationMessage() and Html.ValidationSummary() helpers are used in the automatically generated Edit and Create views by the ASP.NET MVC.
To create a view, the following steps are to be followed:

i) In the product controller,right click on the Create() action and then select the option Add View.
ii) Now check the checkbox labeled in the Add View dialog and create a strongly-typed view.
iii) Select the product class from the View data class dropdownlist.
iv) Now, select Create from the view content dropdownlist.
v) Finally, click on the Add button.


Is it possible to create a MVC Unit Test application in Visual Studio Standard ?


No, It is not possible to create a MVC Unit Test application in Visual Studio Standard.
It is also not possible to create in Visual Studio Express.
It is possible to create only in Visual Studio Professional and Visual Studio Enterprise Versions.


What is Glimpse ?


It is an Open Source platform for gathers and presents detailed diagnostic information about the execution of your web application.It tells you exactly what's going on with each request.

We used in a similar manner to client side diagnostics and debugging tools like FireBug or Chrome Developer Tools.

It is used to reveal what is happening within your ASP.NET MVC and WebForms sites.




How to enable JQuery intellisense support in MVC?


By default, visual studio doesn't provide Jquery intellisense support, but it can be achieved by adding vsdoc.js file to razor view.

<script src="~/script/jquery-1.7.1-vsdoc.js" type="text/javascript"></script>

No te : If statement prevents the rendering of script tag into the Html source code and it used only by visual studio for Jquery intellisense support.



Difference between Asp.Net MVC and Webforms?


1. Webform follows an event-driven development model whereas Mvc follow Model, View, Controller design pattern.

2. Webform has server controls whereas Mvc has Html helpers for creating UI of application. Webforms has state management techniques whereas Mvc doesn't have automatic state management techniques.

4. Webform has file- based Urls means file name exists in Url whereas Mvc has route-based Url.

5. In webform, webforms(Aspx) are tightly coupled to code-behind (Aspx.cs) whereas in Mvc, Views and logic are kept separately.

6. Webform has Master page for consistent look and feel whereas in Mvc layout is for this.

7. Webform has User Controls for code re-usability whereas in Mvc partial view is for this.


What is partial view in Asp.Net Mvc?


A partial view is like as user control in Asp.Net web form. Partial views are reusable views like as Header and Footer. It has .csHtml extension.
Partial and RenderPartial Html method renders partial view in Mvc razor.

<div>@ { Html.RenderPartial("_Comments") } </div>


What is strongly typed view in MVC?


Strongly type view is used for rendering specific type of model object. By specifying the type of data we get intellisense for that model class. View inherits from Viewpage whereas strongly typed view inherits from Viewpage<T> where T is type of the model.


What is significance of 'using' in MVC?


Content Here.....
It ensures that an object is disposed when it goes out of scope.


How to add stylesheet in view in Asp.Net Mvc?


Add stylesheet :

<link rel="StyleSheet" href="@Href(~Content/Site.css")" type="text/css"/>


Share Your Source Code or Article

Do you have source code, articles, tutorials, web links, and books to share? You can write your own content here. You can even have your own blog.

Submit now...