Introduction to .NET Framework

Po Feng, Tsai

How a program is composed and executed A program

Written by you but executed by a machine (computer)

For programmers C,C++,Fortran,Basic

For machines Architecture dependent instruction set (in bi

nary forms) Translation is required

How a program is composed and executed

Source Codes

Compiler

Assembler Object Codes

Linker

Loader

Assembly Codes

Hardware Architecture

Problems for a programmer

Platform dependent Windows ? Linux ?

Architecture dependent X86 ? ARM? PPC?

Interfacing with each others An isolated virtual framework layer

The .NET Framework To provide a convenient and united develo

pment and execution environment C#, VB.NET, C++.NET & Jscript.NET CLR (Common Language Runtime) FCL (framework class library)

Languages integration CTS (Common Type System) CLS (Common Language Specification) CLR

The .NET Framework Framework class library

Lower level: (Base class library) Core data type (integer, string, float, object) Fundamental constructs (collection, I/O …) Access to resources (Networking, file system…) Interface to core execution (Threading, debugging

…) Upper level:

SQL ADO.NET XML Web services

The .NET Framework

Compilation

Source codes are compiled into MSIL (MS Intermediate Language) for the first step

Metadata is used to keep the content information, such as parameters, methods, of the file

Execution CLR is the execution engine of .NET

framework application Virtual machine

It manages the following services Code management Memory management Conversion IL into native code Exception handling Debugging

Compilation & Execution

JIT (Just In Time)

Very popular technique used in various virtual machines Machine codes are generated Fast Compiles as needed

Introduction to C#

Po Feng, Tsai

Getting started Visual C# 2005 Express

http://www.microsoft.com/taiwan/vstudio/express/visualcsharp/

System Requirements: Processor Minimum: 600 megahertz (MHz) Penti

um processorRecommended: 1 gigahertz (GHz) Pentium processor

RAM Minimum: 192 megabytes (MB)Recommended: 256 MB

Hard Disk: Up to 1.3 GB of available space may be required

About C#

C# is announced in July 2000 C# includes the support for

structured, component-based, object-oriented programming Very easy to use Modern programming

Example 1: HelloWorld

In the console window:

Hello World

The Class

A type defines a thing including its properties and behaviors A class is used to define a new type Blueprints

The Method

Behaviors are defined by methods A method is a function owned by your cla

ss Defines what you can do or how it behav

es Usually you can tell what it is for from its nam

e WriteLine()

The Method

Declare a method Keyword: void

The program entry function Main() The program ends when Main() exits

The comments

You can add your own comments by // /* ……… */ /// (used by Visual Studio)

Namespace Tremendous number of types of the .NET Framewo

rk Class Library Each class in C# must have a unique name

Name collision Example (two engineers)

Jim: Science.software.engineer Charlotte: transportation.train.engineer System.Console.WriteLine();

Keyword: using using System; using System.Console; (does not compile !)

Console object

This is a console program No GUIs

Monitor is managed by an Console object It has many behaviors (methods)

WriteLine() Write()

Console.WriteLine()

The Dot operator ( . )

You can use the dot operator to access a method (or data) of a class or object

You can use the dot operator to specify the sub-namespace

Please keep in mind: C# is case-sensitive

The static keyword

It is used to indicate that you can invoke Main() without first creating an object of type HelloWorld

This issue will be covered in later sections

Developing the HelloWorld Console mode (start cmd)

Need .NET Framework SDK csc HelloWorld

Use Visual Studio .NET (Integrated Development Environment)

Using VS .NET

File New Project Select “Console Application”

Using VS .NET

Compile & Run

Compile Build Build Solution Ctrl+shift+B

Run Debug Start Without Debugging F5 (debug) or Ctrl-F5

HelloWorld.exe Contains op-codes written in MSIL Read-only segment

Inserted with standard win32 executable header

Jumps to the JIT compiler JIT compiler

Generating native instructions (like a normal exe file)