Distributed Systems Tutorial 1 - Getting Started with Visual C#.NET

2 Course Info  Home page:  Three Mandatory Programming Assignments  Requirements:  Working knowledge of Java / C#  Basic knowledge of OOP concepts  Basic knowledge of network concepts (sockets, protocols)  No textbook, look at the home page for manuals, tutorials and additional resources

3 Hello World application  Development in Visual Studio is organized around solutions, which contain one or more projects. For this tutorial, we will create a solution with a single C# project.  Creating a New Project In the Visual Studio.NET environment, select File | New | Project from the menu.

4 Hello World application cont.  Select Visual C# Projects on the left and then Console Application on the right..

5  Specify the name of your project and enter the location in which to create the project. The project directory will be created automatically by Visual Studio  Click OK and you're on your way!

6 Class1.cs  using System;  namespace HelloWorld  {  class Class1  {  static void Main(string[] args)  {  Console.WriteLine("Hello C# World!");  }

7 Namespaces  Namespaces are used to define scope in C# applications  Multiple source code files can contribute to the same namespace  The using directive permits you to reference classes in the namespace without using a fully qualified name  class Class1  { static void Main(string[] args) { System.Console.WriteLine ("Hello, C#.NET World!"); }  }

8 Namespaces cont.  using System;  class Class1  { static void Main(string[] args) { Console.WriteLine ("Hello, C#.NET World!"); }  }  When the compiler parses theConsole.WriteLine method, it will determine that the method is undefined.  It will search through the namespaces specified with the using directives and will find the method in the System namespace and will compile the code.

9 Namespaces cont.  Note that using directive applies to namespaces and not to classes  In the example: System is the namespace Console is the class WriteLine is a static method belonging to Console  Therefore the following code would be invalid:

10  using System.Console; // ERROR: Can’t use a using directive with a class  class Class1  { static void Main(string[] args) { WriteLine ("Hello, C#.NET World!"); }  }  But its possible: using output = System.Console; //alias output.WriteLine(“Hello, C#.NET World”);

11 Skeleton  using  namespace  class  { public static void Main() { // TODO: Add code to start application here }  }  Notice that the angle brackets denote where you need to supply information.