Introduction to the C# Programming Language for the VB Programmer

1. Introduction to the C# Programming Language for the VB Programmer

2. Lecture Overview • Compilation and execution of programs • Some key terms • Introduce the C# programming language for the VB developer • Mention some important features of the Visual Studio .NET environment • Pass along some editing tips and tricks

3. Program Compilation • The .NET languages are compiled languages • Code is compiled from the source language (VB, C#, etc..) into machine independent assembly language (MSIL) • MSIL is converted to executable through JITing (Just in time)

4. Program Execution (1) • .NET applications use the Common Language Runtime (CLR) and are executed as Managed Code • Libraries are stored in framework classes • Your code and framework classes are executed by the CLR

5. Program Execution (2)

6. Fundamentals of .NET and C# (1) • Unified type system (Common Type System) • Unified run-time engine with memory management built-in (Common Language Runtime) (Garbage collection) • It’s a type safe language • Static types are enforced at compile time rather than at run time

7. Fundamentals of .NET and C# (2) • Classes encapsulate functionality and have methods, properties (object orientation) • Classes implement interfaces • See Figure 1.1

8. C# Development and Runtime Model

9. Assemblies and Namespaces • Assemblies are physical – Namespaces are logical • An assembly may contain one or more namespaces • The .NET Framework is just a bunch of assemblies • Namespaces are organized into a hierarchy • Namespaces are connected together with a dot (.) • System namespace contains components developed by the .NET team • Microsoft namespace contains components developed by Microsoft but outside of the .NET development team • We references these assemblies and namespaces from our applications

10. Common Assemblies • System.dll defines the primary data types • System.Data.dll defines the components that make up ADO.NET • System.Drawing.dll contains the components used to draw various shapes to an output device • Forms and printers are output devices • System.Windows.Forms.dll contains components to implement desktop forms • System.XML.dll used to process XML documents

11. Common Namespaces • System namespace contains fundamental classes • System.Data namespace contains classes supplying data access capabilities • ADO.NET • System.Drawing provides access to the Graphical Device Interface allowing shapes to be drawn to forms and printers • System.IO provides access to files • System.Windows.Forms supplies the capabilities to create forms and control instances on those forms

12. Adding an Assembly Reference

13. Importing and Using Namespaces • By default, you must fully qualify class and method names • System.IO.StreamReader for example • In VB, the Imports statement allows unqualified references • Imports System.IO • In C#, it’s the using statement • using System.IO;

14. Project Structure • Everything is the same as VB • Solution file, project file, program files • Namespace references • Modules have a file suffix of .cs instead of .vb • Application startup works a bit differently • VB uses a form or Sub Main • C# has a “special” procedure named Main()

15. Solution Explorer • Shows all relevant project files

16. And now for the all Famous Hello World • Create a new C# Console project

17. Program.cs • using statements replace Imports statement

18. Program.cs • namespace forms the outer block • { } marks a block

19. Program.cs • namespace blocks contain classes, which contain properties and methods

20. Program.cs • The Main() method is called the entry point • It’s where program execution begins • Must be declared as static • Method can return either a void or an int

21. Program.cs • Methods (Main) contain local variable declarations and executable statements