IEG 3080 Tutorial 1

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IEG 3080 Tutorial 1

• Raymond Lam

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Outline

• Overview of .Net
• Assembly
• Object Oriented Programming
• Assignment 1 2
• Debug with VS .Net 2005

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Overview of .Net
Figure extracted from M. Chang, Lecture Note 1,
p.45
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Overview of .Net

• Support various programming language
• With CLR (Common Language Runtime), all languages
  are compiled into the same intermediate language
  (MSIL) code, similar to JVM in java
• Support cross-language inheritance(e.g. a VB
  class derived from a C class)

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Overview of .Net

• Disadvantage
• Slower response due to loading time for
  converting byte code (Slower than C)
• Non-multiplatform
• MS platform only,
• Mono project provides alternative to run .Net on
  Linux platform. http//www.mono-project.com/Main_P
  age

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Assembly

• What is an assembly?
• A library component
• Basic unit of a binary file in .Net
• Byte code of single or multiple source files
• With the assembly, programmers can simply reuse
  the implementation without knowing the source
  code
• E.g. abc.dll, xyz.dll
• Notes Not all dll are generated by .Net!!!

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Assembly

• Make a sharable component
• By command
• Using Visual Studio 2005 Command Prompt, not the
  Microsoft Command Prompt (unless you have set the
  PATH)
• E.g. csc /tlibrary HelloMsg.cs
• Output HelloMsg.dll

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Assembly

• By Visual Studio .Net 2005
• Create a Class Library, but not Application

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Assembly

• To use a sharable component
• By command
• E.g. csc /tlibrary HelloMsg.cs
• csc /rHelloMsg.dll HelloApp.cs
• By Visual Studio .Net 2005

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Assembly
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Assembly

• A reference is added to the project
• Simply build HelloApp project only, and the
  output is located at project path\bin\Debug
  or project path\bin\Release
• There should be 2 major outputs, a Hello.exe and
  HelloMsg.dll
• The exe and the dll must be in the same folder
  (unless you have registered the dll in GAC)

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Assembly

• Strong-name Assembly
• Distribute the library component authenticity and
  integrity check
• By public and private key algorithm
• (GAC) Global Assembly Cache
• Centralize the shared library (Strong-name
  assembly only)
• Located at system root/assembly
• Dont try to uninstall the assembly which you do
  not know what it is, otherwise your computer may
  be fail to boot up next time

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Assembly

• Example (refer to Lecture Notes P.56)
• Generate the key filesn k myKey.snk
• Add code to source file to specify version and
  key info
• if STRONG
• assembly System.Reflection.AssemblyVersion(1.0.
  0.0)
• assembly System.Reflection.AssemblyKeyFile(myKe
  y.snk)
• endif
• Compile
• csc /defineSTRONG /tlibrary /outHelloMsg.dll
  HelloMsg.cs
• Add to GAC
• gacutil.exe /if HelloMsg.dll

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Object Oriented Programming

• Encapsulation
• Inheritance
• Polymorphism
• Delegation

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OOP - Encapsulation

• Hide the complexity from the outside world
• Only expose the interface
• Everything acts as a black box, you can only see
  the input and output
• Reason
• The less detail of the implementation you know,
  the easier it is when you change your
  implementation
• Other implementations will not be affected if the
  interface has not been changed

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OOP - Encapsulation

• Easy for the maintenance of large project
• Once the interface are compromised, it is no need
  to know what the implementation is
• Easy for further development, e.g. extension,
  version upgrade
• Import to develop large solution, e.g. ERP
  (Enterprise Resource Program), DMS (Document
  Management System), etc

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OOP - Encapsulation

• Visibility
• public (PacalCasing)
• Accessible from anywhere
• private (camelCasing)
• Only accessible in the same class
• protected
• Only accessible in the same class and its
  subclass
• internal
• Only accessible within assembly (name space)
• protected internal
• Only accessible within assembly or the subclass

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OOP - Inheritance

• Object with similar properties can belong to a
  more general object
• Better Structure
• E.g.

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OOP - Inheritance

• Account Bank inherit Object
• Trivial
• Account is inherited by Saving Account Current
  Account
• Because saving and current account have similar
  properties
• Deposit and Withdraw

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OOP Inheritance Example
Child class
Parent class
Internal variable

• Account

• Saving Account

• public class Account
• protected int _balance 0
• public virtual string GetName()
• return Account
• public int GetBalance ()
• return _balance
• public virtual void Deposit (int amount)

• public class Saving Account
• public override string GetName() return
  Saving
• public override void Deposit (int amount)

camelCasing
Override method
PascalCasing
Implementation
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Polymorphism

• One interface, multiple implementation
• E.g. Account accounts new Account2account
  s0 new SavingAccount()accounts1 new
  CurrentAccount()
• accounts0.Deposit(100)accounts1.Deposit(30
  0)foreach (Account account in accounts)
  Console.WriteLine(account.GetName()
  account.GetBalance())
• Output Saving 100 Current 300

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Assignment

• Assignment 1
• GAC practice
• Assignment 2
• OOP practice
• Try to think in OOP way
• Prevent using C coding style
• Do earilier

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Debug with VS.Net 2005
Set break point
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Debug with VS.Net 2005
You can even drag the pointer to any place in the
same method

• Useful Reference
• MSDN - http//msdn2.microsoft.com/en-us/default.as
  px