Woher kommt die Variable "aTimer" in diesem MSDN-Beispiel?

Question

ich am Beispiel

using System; 
using System.IO; 
using System.Collections.Generic; 
using System.Timers; 

public class Example 
{ 
    private static Timer aTimer; 
    private static List<String> eventlog; 
    private static int nEventsFired = 0; 
    private static DateTime previousTime; 

    public static void Main() 
    { 
     eventlog = new List<String>(); 

     StreamWriter sr = new StreamWriter(@".\Interval.txt"); 
     // Create a timer with a five millisecond interval. 
     aTimer = new Timer(5); 
     aTimer.Elapsed += OnTimedEvent; 
     // Hook up the Elapsed event for the timer. 
     aTimer.AutoReset = true; 
     sr.WriteLine("The timer should fire every {0} milliseconds.", 
        aTimer.Interval); 
     aTimer.Enabled = true; 


     Console.WriteLine("Press the Enter key to exit the program... "); 
     Console.ReadLine(); 
     foreach (var item in eventlog) 
      sr.WriteLine(item); 
     sr.Close(); 
     Console.WriteLine("Terminating the application..."); 
    } 

    private static void OnTimedEvent(Object source, ElapsedEventArgs e) 
    { 
     eventlog.Add(String.Format("Elapsed event at {0:HH':'mm':'ss.ffffff} ({1})", 
            e.SignalTime, 
            nEventsFired++ == 0 ? 
             0.0 : (e.SignalTime - previousTime).TotalMilliseconds)); 
     previousTime = e.SignalTime; 
     if (nEventsFired == 20) { 
      Console.WriteLine("No more events will fire..."); 
      aTimer.Enabled = false; 
     } 
    } 
} 
// The example writes output like the following to a file: 
//  The timer should fire every 5 milliseconds. 
//  Elapsed event at 08:42:49.370344 (0) 
//  Elapsed event at 08:42:49.385345 (15.0015) 
//  Elapsed event at 08:42:49.400347 (15.0015) 
//  Elapsed event at 08:42:49.415348 (15.0015) 
//  Elapsed event at 08:42:49.430350 (15.0015) 
//  Elapsed event at 08:42:49.445351 (15.0015) 
//  Elapsed event at 08:42:49.465353 (20.002) 
//  Elapsed event at 08:42:49.480355 (15.0015) 
//  Elapsed event at 08:42:49.495356 (15.0015) 
//  Elapsed event at 08:42:49.510358 (15.0015) 
//  Elapsed event at 08:42:49.525359 (15.0015) 
//  Elapsed event at 08:42:49.540361 (15.0015) 
//  Elapsed event at 08:42:49.555362 (15.0015) 
//  Elapsed event at 08:42:49.570364 (15.0015) 
//  Elapsed event at 08:42:49.585365 (15.0015) 
//  Elapsed event at 08:42:49.605367 (20.002) 
//  Elapsed event at 08:42:49.620369 (15.0015) 
//  Elapsed event at 08:42:49.635370 (15.0015) 
//  Elapsed event at 08:42:49.650372 (15.0015) 
//  Elapsed event at 08:42:49.665373 (15.0015) 

von https://msdn.microsoft.com/en-us/library/system.timers.timer.interval(v=vs.110).aspx

und bin gespannt, wo aTimer herkommt, da ich es in der Datei definiert überall nicht sehen. Ich erhalte einen Compilerfehler, wenn ich diesen Code in Visual Studio kopiere.

Answer 1

Es wird definiert:

private static Timer aTimer; 

und zugewiesen:

aTimer = new Timer(5); 

Answer 2

using System; 
using System.IO; 
using System.Collections.Generic; 
using System.Timers; 

public class Example 
{ 
    private static Timer aTimer; 

Letzte Zeile dieses Codes. Drücken Sie Strg + F und markieren Sie Alle (Mozilla Firefox), suchen Sie nach aTimer

Answer 3

Die static void Main ist der Zugriffspunkt des Programms.

Es wird am Anfang ausgeführt werden.

Und es wird aTimer einen Wert zuweisen.

public class Example 
{ 
    private static Timer aTimer; 
    ... 

    public static void Main() 
    { 
     ... 
     aTimer = new Timer(5); 
     ... 
    } 
    ... 
}