Introduction to asp

Introduction to ASP.NET

The Evolution of Web Development

• Standards such as HTML (Hypertext Markup Language) and XML (Extensible Markup Language) were created

• Need to develop languages and programming tools that could integrate with the Web

The Early Web Development World

• Separate, tiny applications that are executed by server-side calls - CGI (Command Gateway Interface)

• Scripts that are interpreted by a server-side resource: Classic ASP (Active Server Pages)

What’s Wrong with Classic ASP

Classic ASP is a solid tool for developing web applications using Microsoft technologies• Length Code• No IDE (integrated development environment) for

developers• ASP Code is interpreted.

ASP.NETSome of the differences between ASP.NET and earlier

web development platforms.

• ASP.NET features a completely object-oriented programming model, event driven, control-based architecture that encourages code encapsulation and code reuse.

• ASP.NET gives you the ability to code in any supported .NET language (including Visual Basic, C#, J#, and many other languages that have third-party compilers).

• ASP.NET is dedicated to high performance.

Seven Important Facts About ASP.NETFact 1: ASP.NET Is Integrated with the .NET FrameworkFact 2: ASP.NET Is Compiled, Not InterpretedFact 3: ASP.NET Is MultilanguageFact 4: ASP.NET Is Hosted by the Common Language

RuntimeFact 5: ASP.NET Is Object-OrientedFact 6: ASP.NET Is Multidevice and MultibrowserFact 7: ASP.NET Is Easy to Deploy and Configure

Seven Important Facts About ASP.NET cont..Fact 1: ASP.NET Is Integrated with the .NET

Framework

• .NET Framework provides massive collection of functionality and grouped into a logical, hierarchical container called a namespace.

• .NET gives the tools/functionality available in .NET framework to web developers.

Fact 2: ASP.NET Is Compiled, Not Interpreted.• ASP.NET applications are always compiled

• ASP.NET applications actually go through two stages of compilation.

• First stage, the C# code you write is compiled into an intermediate language called Microsoft Intermediate Language (MSIL), or just IL.

• The second level of compilation happens just before the page is actually executed.

Fact 3: ASP.NET Is Multilanguage• Supports multiple languages for writing server side code.

• the code is compiled into IL

Fact 4: ASP.NET Is Hosted by the Common Language Runtime

Benefits of CLR:• Automatic memory management and

garbage collection• Extensible metadata(assembly)• Structured error handling• Multithreading

Fact 5: ASP.NET Is Object-Oriented.

• ASP.NET is truly object-oriented.

• Web Developer can also exploit all the conventions of an OOP

Fact 6: ASP.NET Is Multidevice and Multibrowser.

• Greatest challenge faced by web developers is developing application, which can run with all browsers

• ASP.NET addresses this problem in a remarkably intelligent way.

Fact 7: ASP.NET Is Easy to Deploy and Configure.

• Deployment is easy.

• Distributing the components your application uses is just as easy.

• Configuration is made easy. (web.config file)

HTML & Web Controls in ASP.NetTwo schools of thoughts when ASP.NET is developed

HTML Controls

Server Side Controls (Web Controls)

render their interface from dozens of distinct HTML elements while still providing a simple object-based interface to the programmer.

Using this model, developers could work with programmable menus, calendars, data lists, validators, and so on.

ASP.NET web controls, which provide a higher level of abstraction and more functionality.

ASP.NET web control tags always start with the prefix asp:

For example, the following snippet creates a text box and a check box:

<asp:TextBox id="myASPText" Text="Hello ASP.NET TextBox" runat="server" />

<asp:CheckBox id="myASPCheck" Text="My CheckBox" runat="server" />

Again, you can interact with these controls in your code, as follows:

myASPText.Text = "New text";myASPCheck.Text = "Check me!“;

The ASP.NET family of web controls includes complex rendered controls (such as the Calendar and TreeView).

Also provides streamlined controls (such as TextBox, Label, and Button), which map closely to existing HTML tags.

Web controls are easy to learn

They’re a natural fit for Windows developers moving to the world of the Web, because many of the property names are similar to the corresponding Windows controls.

Toolbox Tabs for an ASP.NET ProjectStandard: This tab includes the rich web server controls

that are the heart of ASP.NET’s web form model.

Data: These components allow you to connect to a database.

Validation: These controls allow you to verify an associated input control against user-defined rules.

Navigation: These controls are designed to display site maps and allow the user to navigate from one page to another.

Login: These controls provide prebuilt security solutions, such as login boxes and a wizard for creating users.

WebParts: This set of controls supports web parts, an ASP.NET model for building componentized, highly configurable web portals.

The Code ModelVisual Studio supports two models for coding

web pages

Inline Code:

This model is the closest to traditional ASP

All the code and HTML markup is stored in a single .aspx file.

Handy model because it keeps everything in one neat package.

Popular for coding simple web pages.

Inline Code Example <%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN”

"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <script runat="server"> protected void Button1_Click(object sender, EventArgs e) { Label1.Text = "Current time: " + DateTime.Now.ToLongTimeString(); } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>Test Page</title> </head> <body> <form id="form1" runat="server"> <div> <asp:Label ID="Label1" runat="server" Text="Click Me!" /> <br /><br /><br /> <asp:Button ID="Button1" runat="server" OnClick="Button1_Click” Text="Button"

/>> </body></div></form</html>

Code-behind:

Separates each ASP.NET web page into two files

an .aspx markup file with the HTML and control tags, and

.cs code file with the source code for the page

provides better organization Separating the user interface from

programmatic logic, keenly important when building complex pages.

How Code-Behind Files Are Connected to Pages

Every .aspx page starts with a Page directive.

This Page directive specifies: language for the page, also tells ASP.NET where to find the associated code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="TestFormCodeBehind.aspx.cs” Inherits="TestFormCodeBehind"%>