Today most of the applications focus on the Internet ,where the applications can be viewed in a standard web browser .Static web pages are based on HTML and CSS. In Order to create more advanced applications, we need more powerful Tools
Before starting learning ASP.NET we have to know the difference between Desktop application and Web application.
Desktop Application: is an application designed to stand alone machines that don’t require the internet for its operation.
Web Application: is application stored at remote server that requires web browser as a client to run and internet for data/resource transfer
To develop application in ASP.Net or any other programming language you have to be familiar about three different layers of an application
1) Presentation Layer where the user interacts with the User Interface layer. For example if we are planning to develop banking application in ASP.Net, your sample User Interface layer will be as follows
2) Business Logic Layer will help develop the code, we will write coding either in C# or VB.Net or in any other programming language you are familiar.
3) Database Layer : data entered in presentation layer stored in database layer for retrieval and updation. Either we can use Sql server or Oracle or any databases to save our data from presentation layer
Interactive thinking from client side and basic coding knowledge is an important prerequisite to develop applications in .Net.
The above 3 layers of ASP.NET WEB APPLICATION ARCHITECTURE is represented by below pictorial representation
We can develop different types of applications by using .Net.ASP.NET is a web application framework developed and marketed by Microsoft to allow programmers to build dynamic web sites. It allows you to use a full featured programming language such as C# or VB to build web applications easily.
Web sites and web pages are classified into two categories:
- Static web pages
- Dynamic web pages
Static Web Pages
- A static web page is a page which has the same content always.
- Content is written in the page itself as plain html.
- Until the author of the web page updates the content, the content remains the same in the static pages.
- HTML files are used to create static web pages.
Example : http://www.google.com/intl/en/about.html.
Dynamic Web Page
- Dynamic web pages get content from the database.
- Content is NOT hard-coded in the page itself.
- Dynamic pages are created using "server side code" when the page is loaded every time.
- Dynamic web pages are created using technologies like ASP, ASP.NET, PHP etc.
INTRODUCTION TO ASP.NET:
- When you type a URL like www.readexpert.com in your web browser and press Enter, the browser sends a request to web server at that address.
- This is done through HTTP ,the hypertext transfer protocol.
- HTTP is the protocol by which web browser and web server communicate. When we request the URL, you send a request to server.
- When server is active and request is valid ,the server accepts the request ,process it and then sends response back to client browser.
- The relationship between request and response is shown in the following figure.
During the processing of the page ,three main areas can influence the way the page eventually end up in the browser are
2) ASP.NET Server Controls:
These controls are placed in your ASPX page and when they are processed ,they emit HTML that is inserted in the page. We will learn more about these server controls in the forthcoming topics.
3) Programming code:
We can embed code either in C# or VB.Net directly in a page.