Difference b/t Asp and Asp.net

What is ASP?

Active Server Pages (ASP), also known as Classic ASP, is a Microsoft's server-side technology, which helps in creating dynamic and user-friendly Web pages. It uses different scripting languages to create dynamic Web pages, which can be run on any type of browser. The Web pages are built by using either VBScript or JavaScript and these Web pages have access to the same services as Windows application, including ADO (ActiveX Data Objects) for database access, SMTP (Simple Mail Transfer Protocol) for e-mail, and the entire COM (Component Object Model) structure used in the Windows environment. ASP is implemented through a dynamic-link library (asp.dll) that is called by the IIS server when a Web page is requested from the server.

What is ASP.NET?

ASP.NET is a specification developed by Microsoft to create dynamic Web applications, Web sites, and Web services. It is a part of .NET Framework. You can create ASP.NET applications in most of the .NET compatible languages, such as Visual Basic, C#, and J#. The ASP.NET compiles the Web pages and provides much better performance than scripting languages, such as VBScript. The Web Forms support to create powerful forms-based Web pages. You can use ASP.NET Web server controls to create interactive Web applications. With the help of Web server controls, you can easily create a Web application.

What is the basic difference between ASP and ASP.NET?

The basic difference between ASP and ASP.NET is that ASP is interpreted; whereas, ASP.NET is compiled. This implies that since ASP uses VBScript; therefore, when an ASP page is executed, it is interpreted. On the other hand, ASP.NET uses .NET languages, such as C# and VB.NET, which are compiled to Microsoft Intermediate Language (MSIL).

In which event are the controls fully loaded?

Page load event guarantees that all controls are fully loaded. Controls are also accessed in Page_Init events but you will see that view state is not fully loaded during this event

How can we identify that the Page is Post Back?

Page object has an "IsPostBack" property, which can be checked to know that is the page posted back.

What is the lifespan for items stored in ViewState?

The items stored in ViewState live until the lifetime of the current page expires including the postbacks to the same page.

What is the difference between SQL notification and SQL invalidation?

The SQL cache notification generates notifications when the data of a database changes, on which your cache item depends. The SQL cache invalidation makes a cached item invalid when the data stored in a SQL server database changes.

Why do you use the App_Code folder in ASP.NET?

The App_Code folder is automatically present in the project. It stores the files, such as classes, typed data set, text files, and reports. If this folder is not available in the application, you can add this folder. One of the important features of the App_Code folder is that only one dll is created for the complete folder, irrespective of how many files it contains.

What is an ASP.NET Web Form?

ASP.NET Web forms are designed to use controls and features that are almost as powerful as the ones used with Windows forms, and so they are called as Web forms. The Web form uses a server-side object model that allows you to create functional controls, which are executed on the server and are rendered as HTML on the client. The attribute, runat="server", associated with a server control indicates that the Web form must be processed on the server.

What are Session state modes in ASP.NET?

ASP.NET supports different session state storage options:

·         In-Process is the default approach. It stores session state locally on same web server memory where the application is running.

·         StateServer mode stores session state in a process other than the one where application is running. Naturally, it has added advantages that session state is accessible from multiple web servers in a Web Farm and also session state will remain preserved even web application is restarted.

·         SQLServer mode stores session state in SQL Server database. It has the same advantages as that of StateServer.

·         Custom modes allows to define our custom storage provider.

·         Off mode disables session storage.

What are the types of Authentication in ASP.NET?

There are three types of authentication available in ASP.NET:

·        Windows Authentication: This authentication method uses built-in windows security features to authenticate user.

·        Forms Authentication: authenticate against a customized list of users or users in a database.

·   Passport Authentication: validates against Microsoft Passport service which is basically a centralized authentication service.

What is the concept of Postback in ASP.NET?

A postback is a request sent from a client to server from the same page user is already working with. ASP.NET was introduced with a mechanism to post an HTTP POST request back to the same page. It’s basically posting a complete page back to server (i.e. sending all of its data) on same page. So, the whole page is refreshed.

In below diagram, when first request is made from client to server for a web page (say a simple registration form), IsPostback property value will be false. It will be a GET request that may be initiated by:

typing a web page URL in a browser window or

using JavaScript window.open method

or, clicking a hyperlink on a webpage page.

After user filled the returned form and presses a button (say submit button, or use JavaScript to submit form), an HTTP Post request is made to server on same page with data as shown in point 3. This time IsPostback property value will be true. Server processes the request and returns a response back to client.

What are the different validators in ASP.NET?

• ·         Required field Validator
• ·         Range  Validator
• ·         Compare Validator
• ·         Custom Validator
• ·         Regular expression Validator
• ·         Summary Validator

What is ViewState?

ViewState is used to retain the state of server-side objects between page post backs.

Where the viewstate is stored after the page postback?

ViewState is stored in a hidden field on the page at client side.  ViewState is transported to the client and back to the server, and is not stored on the server or any other external source.

How long the items in ViewState exists?

They exist for the life of the current page.

Is it possible to create web application with both webforms and mvc?

Yes. We have to include below mvc assembly references in the web forms application to create hybrid application.

• ·         System.Web.Mvc
• ·         System.Web.Razor
• ·         System.ComponentModel.DataAnnotations
• ·         System.Web.Mvc
• ·         System.Web.Razor
• ·         System.ComponentModel.DataAnnotations

What is the good practice to implement validations in aspx page?

Client-side validation is the best way to validate data of a web page. It reduces the network traffic and saves server resources.

What is the difference between web config and machine config?

Web config file is specific to a web application where as machine config is specific to a machine or server. There can be multiple web config files into an application where as we can have only one machine config file on a server.

What is MVC?

MVC is a framework used to create web applications. The web application base builds on  Model-View-Controller pattern which separates the application logic from UI, and the input and events from the user will be controlled by the Controller.

Difference between ASP.NET MVC and ASP.NET WebForms?

ASP.NET Web Forms uses Page controller pattern approach for rendering layout, whereas ASP.NET MVC uses Front controller approach. In case of Page controller approach, every page has its own controller, i.e., code-behind file that processes the request. On the other hand, in ASP.NET MVC, a common controller for all pages processes the requests.

What is Routing in ASP.NET MVC?

In case of a typical ASP.NET application, incoming requests are mapped to physical files such as .aspx file. On the other hand, ASP.NET MVC framework uses friendly URLs that more easily describe user’s action but not mapped to physical files. Let’s see below URLs for both ASP.NET and ASP.NET MVC.

What is the difference between ViewData, ViewBag and TempData?

In order to pass data from controller to view and in next subsequent request, ASP.NET MVC framework provides different options i.e., ViewData, ViewBag and TempData.

Both ViewBag and ViewData are used to communicate between controller and corresponding view. But this communication is only for server call, it becomes null if redirect occurs. So, in short, it's a mechanism to maintain state between controller and corresponding view.

ViewData is a dictionary object while ViewBag is a dynamic property (a new C# 4.0 feature). ViewData being a dictionary object is accessible using strings as keys and also requires typecasting for complex types. On the other hand, ViewBag doesn't have typecasting and null checks.

TempData is also a dictionary object that stays for the time of an HTTP Request. So, Tempdata can be used to maintain data between redirects, i.e., from one controller to the other controller.

What are Action Methods in ASP.NET MVC?

I already explained about request flow in ASP.NET MVC framework that request coming from client hits controller first. Actually MVC application determines the corresponding controller by using routing rules defined in Global.asax. And controllers have specific methods for each user actions. Each request coming to controller is for a specific Action Method. The following code example, “ShowBooks” is an example of an Action method.

Important Note: All public methods of a Controller in ASP.NET MVC framework are considered to be Action Methods by default. If we want our controller to have a Non Action Method, we need to explicitly mark it with NonAction attribute as follows: