Lecture introduction to Csharp

 should be very comfortable writing OO code  we will not cover much if any basic programming languages  not even teach you OO style except wrt C#  expected to write all code in OO st

Introduction to C#

Tom Roeder

CS 215 2006fa

Goals of the course

 should be very comfortable writing OO code

 we will not cover much if any basic programming

languages

 not even teach you OO style (except wrt C#)

 expected to write all code in OO style

 S/U only

 will not be giving a detailed grade

 show me that you understand the concepts, and can write C# code

soon

 must be completed by the end of the course

 Do not submit work that is not your own

minimum penalty: U in the course

Useful Tools

 Visual C#

 Express: Google “Visual C# Express”

 in Visual Studio: MSDNAA

 Mono: http://www.go-mono.com

 Open Source impl for Linux: not quite at 2.0

 Rotor:

http://msdn.microsoft.com/net/sscli

 Shared Source impl for Windows (through 2.0)

 Used to work on BSD / OS X, too

Useful Tools

 yet another open source impl

 we will use this for homework

 turn on your email notifications!

://www.cs.cornell.edu/courses/cs215

 will post lectures online

 as well as any errata for the homework

 You all will have accounts

 MSDNAA access: let me know if you don’t

currently have it

 http://www.csuglab.cornell.edu/userinfo.html

 Visual Studio NET 2005 should be installed there

 Syllabus (10 more lectures)

 C# constructs: 5 lectures

 Types, Delegates, Generics, Reflection, Iterators

 NET Memory Management: 1 lecture

 Topics: 4 lectures

 C# 3.0, Threading, Security, MSIL, MSH

Quiz 1

 Each class will begin with a quiz

 not for credit but for knowledge

 but I will collect them and see what you know

 Today’s quiz will be on

prerequisites

 OO programming, mainly to do with Java

 If you don’t know Java, but do have OO

experience, it’s OK

 talk to me after if you have trouble

What is NET?

(CLS)

Common Language Runtime

Building Blocks (e.g for Services)

Services: NET and COM+

SQL Server BizTalk

Languages : C#, Visual Basic, etc

What is the CLR?

Class Loader

MSIL to Native Compilers (JIT)

Code Manager

Garbage Collector (GC)

Security Engine Debug Engine Type Checker Exception Manager Thread Support COM Marshaler

Base Class Library Support

What is the CTS?

 A set of common types

 any language that runs in CLR should implement

 no syntax specified

 Languages often define aliases

 For example

 CTS defines System.Int32 – 4 byte integer

 C# defines int as an alias of System.Int32

What is the CTS?

What is the CLS?

features

 how methods may be called

 when constructors are called

 subset of the types in CTS are allowed

 Code that takes UInt32 in a public method

 UInt32 is not in the CLS

 not marked is assumed to mean not compliant

The Class Libraries

 The common classes used in many

programs

 like Java Class Library

 eg.

 System.Console.WriteLine

 XML, Networking, Filesystem, Crypto, containers

 Can inherit from many of these classes

 Many languages run on NET framework

 C#, C++, J#, Visual Basic

 private: local directory, not accessible by others

 shared: well-known location, can be GAC

 strong names: use crypto for signatures

COM vs NET

 Historically, COM provided this integration

 support for interfaces and interaction

 given a GUID, lookup the type library

 dynamically instantiate class

 do RPC to make calls in many cases

 Difficult to get right

 software engineering problems

not type safe at all

ASP.NET and ADO.NET

 Use NET languages in web pages

 thus can write typesafe code

 server-side or client-side

 Sharepoint interactions

 can log in

 Use the CLR to access databases

 in the manner of ODBC

 provides classes for access

Windows PowerShell

 New shell originally for MS Vista

 available for WinXP/2k3

 native NET

 instantiates arbitary NET classes and accesses them

 Also can access COM objects

 Allows better interaction with

programs

 Can it surpass bash and others?

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Constructions of Note

 Console.Write(Line)

 Takes a formatted string: “Composite Format”

 Indexed elements: e.g., {0}

 can be used multiple times

 only evaluated once

 {index [,alignment][:formatting]}

 also can use as in Java

 “Test “ + a

More C# : basic inheritance

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