Csharp/CSharp Tutorial/Language Basics/Main — различия между версиями

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м (1 версия)
 
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Текущая версия на 15:19, 26 мая 2010

Looking for Command-Line Options

<source lang="csharp">class MainClass {

 static void Main(string[] args)
 {
   
   if(args[0][0]=="-")
   {
       //This parameter is an option
   }
 }

}</source>

Looking for Command-Line Options (Simplified)

<source lang="csharp">class MainClass {

 static void Main(string[] args)
 {
   
   string arg = args[0];
   if(arg[0] == "-")
   {
       //This parameter is an option
   }
 }

}</source>

Main Entry Point

<source lang="csharp">Main is the entry point method for a C# application. static void Main() {

   // main block

} static int Main() {

   // main block

} static void Main(string [] args){

   // main block

} static int Main(string [] args){

   //

}</source>

The Main Function

All C# applications begin execution by calling Main( ).


<source lang="csharp">using System; class MainClass {

   public static void Main()
   {
       Console.WriteLine("Hello, Universe!");
   }

}</source>

Hello, Universe!

The main function: returning an int status

<source lang="csharp">using System; class MainClass {

   public static int Main()
   {
       Console.WriteLine("Hello, Universe!");
       return(0);
   }

}</source>

Hello, Universe!

The Main Function: use foreach to loop through command-line parameters

<source lang="csharp">using System; class MainClass {

   public static void Main(string[] args)
   {
       foreach (string arg in args)
       Console.WriteLine("Arg: {0}", arg);
   }

}</source>

Using foreach to loop through the parameter from Main function

<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;

   class Program
   {
       static void Main(string[] args)
       {
           Console.WriteLine("{0} command line arguments were specified:",args.Length);
           foreach (string arg in args)
               Console.WriteLine(arg);
       }
   }</source>