1. Introduction to .NET Florin Olariu & Andrei Arusoaie
“Alexandru Ioan Cuza”, University of Iași
Department of Computer Science

2. Organization People: Florin Olariu & Andrei Arusoaie & Dan Nastasa
14 weeks (full activity) + 2 weeks for evaluation
Final grade = round(40% * Exam + 60% * Lab + 10% * Kata’s)
Exam: max 40 points, midterm exam
Lab: max 70 points = 20 lab activity + 40 semester project + 10 coding kata’s
* bonus points!
Criteria: min 50 (Exam + Lab)
WEB:

3. Resources Books/movies: Microsoft: Getting started:
(create your Microsoft account!)
Ask for books using Facebook
Microsoft:
Getting started:

4. Questions? Contact: Facebook: andrei.arusoaie@gmail.com
Facebook:
Introduction to .NET (click!)

5. Motivation Why C#? Open source
The platform is new (written from scratch)
Is the first time when we can say: “Write once => deploy everywhere!”
It has been oriented to performance
It has a very strong middleware system built-in
According with the trends it is the most recommended high-level language that should be learned in
The sources can be found in github.

6. Goal Learn how to: Write business applications using .NET Core 2.0
Using best practices in writing maintainable software
How to use design patterns
How to use architectural patterns
How to write decoupled code
How to build responsive web applications
How to work in teams using Agile Development (SCRUM approach)
How to prepare for an interview .NET oriented
(Andrei&Florin&Dan)Open for new challenges according with your(and market) needs

7. Agenda What is .NET Core? What is .NET Framework?
Overview on ASP.NET Core
What is new about this framework?
Sample: Developing sample web application.
OOP in .NET Core
NET Framework – C# access modifiers and other common types

8. What is .NET Core? What is .NET Framework?

9. What is .NET Core? What is .NET Framework?
Open Source.
Developed & run on Cross Platform.
Built on the .NET Core runtime & also on .NET Framework.
Facility of dynamic compilation.
Built in Dependency Injection (DI).
MVC & Web API Controller are unified, Inherited from same base class.
Smart tooling (Bower, NPM, Grunt & Gulp).
Command-line tools.
What is .NET Framework?
Developed and run on Windows platform only.
Built on the .NET Framework runtime.
Supported (MVC, Web API & SignalR) Dependency Injection (DI).
MVC & Web API Controller are separated.
Image source:

10. Overview on ASP.NET Core

11. Overview on ASP.NET Core
A unified story for building web UI and web APIs
Integration of modern client-side frameworks and development workflows
A cloud-ready environment-based configuration system
Built-in dependency injection
New light-weight and modular HTTP request pipeline
Ability to host on IIS or self-host in your own process
Built on .NET Core, which supports true side-by-side app versioning
Ships entirely as NuGet packages
New tooling that simplifies modern web development
Build and run cross-platform ASP.NET apps on Windows, Mac and Linux
Open source and community focused

12. What is new about this framework?
Note: show the trick with dot.net!!!! -> open an browser and write down dot.net!!!!

13. What is new about this framework?
Cross platform
Cross platform
First thing that needs to be signaled here is that till this version all the others .NET Framework version 1.0->4.5 were for development only for/in Windows platforms.
During this period there was a framework called Mono Framework, open source and compatible with .NET
With this new version Microsoft changed completely their attitude and created this new platform that now can be used not only on Windows but also on other platforms like: Mac or Linux.
In the past the only IDE available to build strong/large applications was Visual Studio. Now we can use any editor (the best one is Visual Code -> can be installed on Mac or Linux as well) and we can execute any program using a console.
To make it work on a cross platform, Microsoft built up a new set of runtime & libraries called CoreCLR and CoreFX which they compiled for every platform and generated builds.
With making .NET Core a Cross Platform, Microsoft removed the tightly IIS bound "System.Web" and made it "Microsoft.AspNetCore" which will work for all platform hosting environment.

14. What is new about this framework?
Cross platform
Open source
Open source
With the world moving towards open source, Microsoft made this framework totally an open source. Also, the source code is available on GIT. You can now easily customize this framework according to your need.

15. What is new about this framework?
Cross platform
Open source
Optimized .NET runtime & libraries
Optimized .NET runtime & libraries
With these changes, Microsoft also made changes to its libraries which were available in our GAC on installation of .NET Framework.
One example that I can think of, is “System” library.
The “System” library consists of many logical libraries, such as System.IO, System.Net, System.Configuration, etc. which getsloaded into memory every time you use “System” library. But, do you think there is a need to load the whole library when only a portion is needed? Suppose I need only System.IO, then my project should only refer System.IO instead of System as a whole. To make it a light weight and optimized, .NET Core now supports nuGet packages for each of this logical library and they will no more refer from GAC (which was available only on Windows platform)

16. What is new about this framework?
Cross platform
Open source
Optimized .NET runtime & libraries
Completely modular
Completely modular
Every time when there was a new feature added in any component of .NET framework, a new version was released by Microsoft.
For example – with ASP.NET MVC, there was a routing concept introduced until ASP.NET MVC 4 which was there in Visual Studio 2012 (.NET framework 4.5).
But with ASP.NET MVC 5, they introduced something called as Attribute Level Routing which was added in Visual Studio 2013 (.NET Framework 4.5.1).
This kind of change in components may lead to introducing new release of framework version.
But now, that is all gone with .NET Core, where everything is nuGet package. It became very easy to upgrade the component as it will introduce the release of nuGet package and not the whole framework. This makes everything modular.

17. What is new about this framework?
Cross platform
Open source
Optimized .NET runtime & libraries
Completely modular
Introduction to CLI
Introduction to CLI
.NET Core also introduces a Command line application called as dotnet.exe. This application allows us to,
create an application 
execute the application
run the Intermediate language
host the CLR for any platform.

18. What is new about this framework?
Cross platform
Open source
Optimized .NET runtime & libraries
Completely modular
Introduction to CLI
Cloud ready environment
Cloud ready environment
With .NET Core, we can build cloud based internet connected applications, like Web Apps, IOT apps & mobile backend.

19. Sample: Developing sample web application
DEMO
Show the code
Explain some parts like: controllers, views, models, startup, routing etc
Explain CLI commands
Host in IISExpress, Self-Hosting,

20. OOP in .NET Core
Inheritance
Inheritance
Classes may derive from exiting classes.
Existing classes are called : parent class. => and it is a generalization of the exiting class.
Inheritance creates an “is –a ” relationship
Example: Employee<=Manager, Architect, Technical Lead, Developer

21. OOP in .NET Core – inheritance
Derived class indicates base class with colon.
Notes:
classes can contain properties and fields (built-in like int, string or custom like other classes or struct’s)
Fields are used to support private methods
Properties are used to expose functionality to other classes

22. OOP in .NET Core - inheritance
Identify : properties, methods/behavior

23. OOP in .NET Core - polymorphism
The possibility of taking many forms.
Method overriding -> modify a method in the derived class : C# in order to be able to use method overriding we need to know: virtual  override.
Virtual exists in base class, override in derived class.

24. OOP in .NET Core - polymorphism

25. OOP in .NET Core - polymorphism
Another important aspect for polymorphism is “method overloading”.
Means: we can have in the same class methods with the same name but different number of parameters.

26. OOP in .NET Core - encapsulation
Encapsulation : a class should have a single responsibility. => don’t forget here, there is another set of principles : SOLID.
Within the class we should have private functionality, that should not be exposed and only a : few well-defined methods that are public.
Question: Why the method should be public?

27. OOP in .NET Core Inheritance Polymorphism Encapsulation
There are 3 pillars in OOP. => Inheritance, polymorphism and encapsulation.

28. NET Framework – C# access modifiers and other common types

29. NET Framework – C# access modifiers and other common types
What is an access modifier?

30. NET Framework – C# access modifiers and other common types
What is an access modifier?
An access modifier is a keyword used to specify the accessibility of a member or a type.

31. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?

32. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private

33. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private

34. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private
public => there is no restriction in regards with accessibility

35. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private

36. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private
protected => access is limited to
the containing class or types derived
from the containing class

37. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private

38. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private
internal => access is limited to
the current assembly

39. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private

40. NET Framework – C# access modifiers and other common types
How many access modifiers exists in C#?
In C# we have four access modifiers
public
protected
internal
private
private => access is limited to
the containing type

41. NET Framework – C# access modifiers and other common types

42. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual

43. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual

44. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const

45. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor

46. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor
Can be initialized only at the declaration

47. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor
Can be initialized only at the declaration
Can be used only by fields

48. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor
Can be initialized only at the declaration
Can be used only by fields

49. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor
Can be initialized only at the declaration
Can be used only by fields
If is initialized via constructor can have different values

50. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor
Can be initialized only at the declaration
Can be used only by fields
If is initialized via constructor can have different values
Is a compile-time constant

51. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
readonly
const
Can be initialized: at declaration or in a constructor
Can be initialized only a the declaration
Can be used only by fields
If is initialized via constructor can have different values
Is a compile-time constant

52. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual

53. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
Can be used for classes and
methods

54. NET Framework – C# access modifiers and other common types
Classes => prevents other classes
to inherit from it.
Methods => prevents from overriding
virtual methods.
Other common types
readonly vs const
sealed
virtual

55. NET Framework – C# access modifiers and other common types
Classes => prevents other classes
to inherit from it.
Methods => prevents from overriding
virtual methods.
Other common types
readonly vs const
sealed
virtual

56. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual

57. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
It is used for: methods, properties
indexer and events.

58. NET Framework – C# access modifiers and other common types
readonly vs const
sealed
virtual
It is used for: methods, properties
indexer and events.
This allows us to override the
behavior in a derived class.

59. One more thing…

60. One more thing…
“Talk is cheap. Show me the code.”

61. One more thing… “Talk is cheap. Show me the code.” ― Linus Torvalds
Write comments only when strictly necessary and keep them in sync with the code.

62. One more thing… “Talk is cheap. Show me the code.” ― Linus Torvalds
Write comments only when strictly necessary and keep them in sync with the code.
Establish a set of shared coding standards

63. One more thing… “Talk is cheap. Show me the code.” ― Linus Torvalds
Write comments only when strictly necessary and keep them in sync with the code.
Establish a set of shared coding standards.
“Any fool can write code that a computer can understand. Good programmers write code that humans can understand.”

64. One more thing… “Talk is cheap. Show me the code.” ― Linus Torvalds
Write comments only when strictly necessary and keep them in sync with the code.
Establish a set of shared coding standards.
“Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” – Martin Fowler

65. Questions
Do you have any other questions?

66. Thanks! See you next time! 