Taking it out for a test drive in Visual C#.NET

Draw Code39 in Visual C#.NET Taking it out for a test drive

To convert your C# program into an executable program, choose Build Build Program1 Visual Studio responds with the following message:

- Build started: Project: Program1, Configuration: Debug Any CPU Cscexe /noconfig /nowarn (and much more)

Compile complete -- 0 errors, 0 warnings Program1 -> C:\C#Programs\ (and more)==Build: 1 succeeded or up-to-date, 0 failed, 0 skipped==

The key point here is the 1 succeeded part on the last line As a general rule of programming, succeeded is good; failed is bad The bad the exceptions is covered in 9 of this minibook To execute the program, choose Debug Start The program brings up a black console window and terminates immediately (If you have a fast computer, the appearance of this window is just a flash on the screen) The program has seemingly done nothing In fact, this is the case The template is nothing but an empty shell An alternative command, Debug Start Without Debugging, behaves a bit better at this point Try it out

Edit the Programcs template file until it appears this way:

using System; namespace Program1 { public class Program { // This is where your program starts static void Main(string[] args) { // Prompt user to enter a name ConsoleWriteLine( Enter your name, please: ); // Now read the name entered string name = ConsoleReadLine(); // Greet the user with the name that was entered ConsoleWriteLine( Hello, + name); // Wait for user to acknowledge the results ConsoleWriteLine( Press Enter to terminate ); ConsoleRead(); } } }

Don t sweat the stuff following the double or triple slashes (// or ///), and don t worry about whether to enter one or two spaces or one or two new lines However, do pay attention to capitalization

Choose Build Build Program1 to convert this new version of Programcs into the Program1exe program From within Visual Studio 2008, choose Debug Start Without Debugging The black console window appears and prompts you for your name (You may need to activate the console window by clicking it) Then the window shows Hello, followed by the name entered, and displays Press Enter to terminate Pressing Enter closes the window You can also execute the program from the DOS command line To do so, open a Command Prompt window and enter the following:

Now enter Program1 to execute the program The output should be identical to what you saw earlier You can also navigate to the \C#Programs\ Program1\bin\Debug folder in Windows Explorer and then double-click the Program1exe file To open a Command Prompt window, try choosing Tools Command Prompt If that command isn t available on your Visual Studio Tools menu, choose Start All Programs Microsoft Visual Studio 2008 Visual Studio Tools Visual Studio 2008 Command Prompt

In the following sections, you take this first C# console app apart one section at a time to understand how it works

The basic framework for all console applications starts as the following:

using using using using System; SystemCollectionsGeneric; SystemLinq; SystemText;

namespace Program1 { public class Program { // This is where your program starts public static void Main(string[] args) { // Your code goes here } } }

The program starts executing right after the statement containing Main() and ends at the closed curly brace (}) following Main() (I explain the meaning of these statements in due course More than that, I cannot say for now) The list of using directives can come immediately before or immediately after the phrase namespace Program1 { The order doesn t matter You can apply using to lots of things in NET I explain the whole business of namespaces and using in the object-oriented programming chapters in Book II