a roadmap to.net ajdan jumerefendi compsci 109 september 19, 2003

A Roadmap to .NETAjdan Jumerefendi

COMPSCI 109

September 19, 2003

Agenda Overview of .NET Data Access using ADO.NET ASP.NET

Web Forms Web Services Web Applications

Development Tools

.Introduction From http://www.microsoft.com/net/basics/: Microsoft .NET

Microsoft software for connecting information, people, systems, and devices. .NET provides XML-based interoperability and is being incorporated across Microsoft's clients, servers, services, and tools. For example, products like Microsoft Windows® and Microsoft Office will use .NET to connect with other systems and applications. For developers, .NET is manifested in the programming model delivered in the Microsoft .NET Framework.

Microsoft .NET Framework An integral Windows component that enables building and running

the next generation of software applications and Web services. It includes technologies for Web services and Web applications (ASP.NET), data access (ADO.NET), smart client applications (Windows Forms), and many others.

.NET Blueprint

Open Internet ProtocolsOpen Internet ProtocolsSOAP, SCL, DISCOSOAP, SCL, DISCO

HTTP, SMTP, XML, WAP, XSDHTTP, SMTP, XML, WAP, XSD

Your Application Your Application and Web Serviceand Web Service

Your Application Your Application and Web Serviceand Web Service

.NET .NET FrameworkFramework

.NET .NET FrameworkFramework

Windows Windows CE, ME, CE, ME,

2000, .NET2000, .NET

Windows Windows CE, ME, CE, ME,

2000, .NET2000, .NETO

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End-UserEnd-UserClientsClients

End-UserEnd-UserClientsClients

OtherOtherApplicationsApplications Using Your Using Your

ServiceService

OtherOtherApplicationsApplications Using Your Using Your

ServiceService

OrchestrationOrchestrationOrchestrationOrchestration

Your Internal ServicesYour Internal ServicesYour Internal ServicesYour Internal Services

.NET Enterprise .NET Enterprise ServersServers

.NET Enterprise .NET Enterprise ServersServers

.NET MyServices.NET MyServices.NET MyServices.NET MyServices

Public Web ServicesPublic Web ServicesPublic Web ServicesPublic Web Services

Visual Visual Studio.NETStudio.NET

Visual Visual Studio.NETStudio.NET

Inside the .NET Framework

Common Language Runtime

Base Framework

Data and XML

Web Services User Interface

VB C++ C#

ASP.NET

Perl Eiffel Cobol

Active Server Pages .NET•High-productivity environment for building and running Web services

Secure, integrated class libraries•Unifies programming models across languages

•Enables cross-language integration

•Factored for extensibility

•Designed for tools


•Executes code, maintains security, handles component “plumbing” and dependencies

An Alphabet Soup CLR – Common Language Runtime CTS – Common Type System (C)IL – (Common) Intermediate Language

also known as: MIL – Microsoft Intermediate Language

CLS – Common Language Specification GC – Garbage Collector


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FrameworksFrameworks

Class loader and layoutClass loader and layout

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GC, stack walk, code managerGC, stack walk, code manager

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Base ClassesBase Classes

Dramatically simplify application development

Provide a robust and secure execution environment

Support multiple programming languages

Simplify deployment and management

Common Type System Static (compile time) typed Object-Oriented

fields, methods, nested types, properties, etc. Object Based – everything is an object Independent of the underlying physical

platform Key feature when addressing program

platform independence

Managed and Unmanaged Code Managed Code – code compiled to IL

Safe Type-checked Bound-checked No need to worry about memory management – Garbage

collection. No more pointers and segmentation faults (Actually,

everything is a pointer but a safe one) Platform Independent

Unmanaged Code – native code .Net makes it possible to integrate both.

.NET Languages The .NET Platform is Language Neutral

• All .NET languages perform the same• You can leverage your existing skills

Microsoft provides:• VB, C++, C#, JScript

Third-parties are building• APL, COBOL, Pascal, Eiffel, Haskell, ML,

Oberon, Perl, Python, Scheme, Smalltalk

Base Classes Hierarchically organized into namespaces Namespace is just a unit of logical/physical

organization Base namespace : System .NET comes with a large set of base classes

implementing IO, Graphics, Networking, Data Access, Security, etc.

A very rich set of classes that can support projects of significant complexity

Other Interesting Topics Assemblies Metadata Execution Model Interoperability Common Language Specification



Development Tools

Why do we Need to Access Data Data access is the heart of any real-world

application Services are dynamic

Require large amounts of data to be filtered and processed

Generate data during its process of execution Provide various functionalities based on the

accumulated data

Data Access Architecture A Data Source (DS)

stores, organizes and manages data

Client (C) establishes a connection with the DS

C accesses DS using SQL

DS processes request and returns result

On the Windows Platform, the preferred and most often used DS is Microsoft SQL Server. Its current version is 2000.

Data SourceClient

SELECT * FROM PRODUCTS WHERE PRD_ID = 2489393

Basic Classes .Net framework provides ready classes for accessing a variety

of data sources Namespaces:

System.Data (general data access classes) System.Data.SqlClient (MSSQL specific classes)

Most important classes: SqlConnection SqlCommand SqlDataReader SqlDataAdapter DataSet DataTable

Establishing and Terminating a Connection

Create an instance of the SqlConnection object Call its Open method. Execute a request Close the connection when done Topics not covered: Connection String, Connection Pooling

SqlConnection myConnection = new SqlConnection("server=(local)\NetSDK;database=pubs;Trusted_Connection=yes");

myConnection.Open();

…. Do Something …

myConnection.Close();

Issuing Commands

Create an instance of SqlCommand, specifying the SQL command text and the connection to be used

Execute the command and store the result Many other possible ways to execute a command

Parameters Different result types

SqlConnection myConnection = new SqlConnection("server=(local)\NetSDK;database=pubs;Trusted_Connection=yes");

SqlCommand myCommand = new SqlCommand("select * from Authors", myConnection); myConnection.Open();DataSet ds = new DataSet();

myCommand.Fill(ds, "Authors"); myConnection.Close();

Storing Retrieved Data Different ways to retrieve and store data Depend on data type and application needs Most versatile class: DataSet Other useful classes:

SqlDataReader SqlDataAdapter

Recommended Practice Stored Procedures

SQL code stored directly in the database server Compiled, optimized, faster Elegant encapsulation and isolation of code

Example: Creating the Stored Procedure

CREATE Procedure GetAuthors

AS SELECT * FROM Authors

Invoking a Stored Procedure// create the command command = new SqlCommand();// attach the stored procedure namecommand.CommandText = “GetAuthors”;// set the type to: StoredProcedurecommand.CommandType = CommandType.StoredProcedure;// attach the connectioncommand.Connection = myConnection;// open the connectionmyConnection.Open();// create a DataSet objectDataSet ds = new DataSet(); // Execute the command and fill the DataSetmyCommand.Fill(ds, "Authors"); // Close the connectionmyConnection.Close();


Web Forms Web Service Web Applications

Web Services

What is it All About? A programming framework built on the common language

runtime that can be used on a server to build powerful Web applications

Enhanced Performance Powerful Simple Secure Provides for rapid development Manageable Makes web programming “REAL” programming. Supports different types of clients

Today’s Environment

The Ingredients of ASP.NET Web Forms Server Controls Web Services Web Applications

Request and Response Objects Request Object – provides access to the

client’s request: Request parameters Type of browser, operating system, ip, etc., Cookiesstring name = (string)Request.QueryString[“name”];

Response Object – used to generate the response for the client:Response.Write(“Hello World”)


Web Forms Web Service Web Applications

Development Tools

Web Forms A scalable common language runtime

programming model that can be used on the server to dynamically generate Web pages

Automate the management of a page’s state across different round trips to the server.

Simple, fast, and elegant mechanism to generate dynamic content

A Basic Form<html> <head> <link rel="stylesheet"href="intro.css"> </head>

<body>

<center>

<form action="intro2.aspx" method="post">

<h3> Name: <input id="Name" type=text>

Category: <select id="Category" size=1> <option>psychology</option> <option>business</option> <option>popular_comp</option> </select>

</h3>

<input type=submit value="Lookup">

<p>

</form>

</center>

</body></html>

Beginning Scripting<%@ Page Language="C#"%>

<html> <head> <link rel="stylesheet"href="intro.css"> </head> <body> <center> <form action="intro2.aspx" method="post">

<h3> Name: <input id="Name" type=text>

Category: <select id="Category" size=1> <option>psychology</option> <option>business</option> <option>popular_comp</option> </select>

</h3> <input type=submit value="Lookup"> <p> <% for (int i=0; i <8; i++) { %> <font size="<%=i%>"> Welcome to ASP.NET </font> <br> <% }%> </form> </center>

</body></html>

Server Controls While we can do all just by using <% and

%>, by using this method we: Have no clean programming style Have to manually manage state across requests

Can use Server controls instead: Just like regular HTML tags with a small

difference: runat=“server”

<asp:label runat=“server” text=“Hello World” />

ASP.NET Web Form<%@ Page Language="C#"%>

<html> <head> <link rel="stylesheet"href="intro.css"> </head>

<body>

<center>

<form action="intro4.aspx" method="post" runat=server>

<h3> Name: <asp:textbox id="Name" runat="server"/>

Category: <asp:dropdownlist id="Category" runat=server> <asp:listitem>psychology</asp:listitem> <asp:listitem>business</asp:listitem> <asp:listitem>popular_comp</asp:listitem> </asp:dropdownlist>

</h3>

<asp:button text="Lookup" runat="server"/>

</form>

</center>

</body></html>

Event Handling Source Code End Result

Lists, Data and Data Binding Data Binding – associating a data source with

a control Intoduction and Examples DataGrid DataList Repeater

Server Controls ASP.NET comes with a set of 45 standard

server controls. Cover most HTML elements and operations ASP.NET makes it possible to develop

custom controls, known also as user controls Introduction to User Controls

Code-Behind Web Forms ASP.NET supports two methods of authoring

dynamic pages. page code is physically declared within the

originating .aspx file. An alternative approach--known as the code-behind

method--enables the page code to be more cleanly separated from the HTML content into an entirely separate file.

Example: Code Result



Development Tools

Introduction WWW is evolving very quickly

Static Pages Somewhat Dynamic Pages Latest: Programmable Web Sites

Provide programming access to different functionalities exported by the web sites Turn the web site into a service – an entitity perfoming something on demand

XML Web Services – define mechanisms, standards and protocols to expose and access functionality Services specify what they offer Clients find this information and execute requests

Based on XML – powerful and extensible mechanism to define and organize data Curent Web Services Protocols and Languages:

WSDL – Web Service Definition Language SOAP – Simple Object Access Protocol

Basic Constructs The .NET framework provides a namespace

System.Web.Services with classes to be used for the construction of xml web services

Most important class: System.Web.Services.WebService

To create a web service – inherit the above class, write some methods to be exposed and prefix them with [WebMethod]. Tell your clients where they can find the service.

A Simple Web Service<%@ WebService Language="C#"

Class="HelloWorld" %>

using System;using System.Web.Services;

public class HelloWorld : WebService {

[WebMethod] public String SayHelloWorld() {

return "Hello World"; }

}

Another Example Simple Calculator Service Consuming the Service



Development Tools

Overview ASP.NET Framework applications consist of

everything under one virtual directory of the Web server

Application is created by simply adding a file to the virtual directory

Can define custom handling of various events: Init Start End

Managing State Two ways:

Using the application Using the Session object

Application Data that is infrequently modified but read often

(global data) Session

Data specific to a user session or request



Development Tools

Visual Studio .NET All-in-One Integrated Development

Environment Write Code, Debug, Execute Access Databases, Remote servers Rich, Detailed Help System.

Resources ASP.NET Quickstart Tutorials

http://rack87.cs.duke.edu/quickstart/aspplus/ .NET Howto-s

http://rack87.cs.duke.edu/quickstart/howto/ ASP.NET official community web site

http://www.asp.net/ Microsoft official .NET web site

http://www.microsoft.com/net/ C# Resources

http://www.csharp-station.com/ MSDN

http://msdn.microsoft.com/library/en-us/dnanchor/html/netdevanchor.asp?frame=true

a roadmap to.net ajdan jumerefendi compsci 109 september 19, 2003

Documents

web applications aspnet

tools common language

web services secure

management slide

language neutral

microsoft windows

net languages

microsoftnet framework