このMSDNの例では、変数 "aTimer"はどこにありますか？

Question

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

から例

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) 

を見て、aTimerが、私はそれがどこでもファイルに定義されて表示されていないので、どこから来るのか興味がありますよ。このコードをVisual Studioにコピー＆ペーストすると、コンパイラエラーが発生します。

Answer 1

に定義されます。

private static Timer aTimer; 

と割り当て：

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; 

このコードの最後の行。 Ctrl + Fキーを押し、すべてをハイライト（Mozilla Firefox）して、aTimerを検索します

Answer 3

static void Mainはプログラムのアクセスポイントです。

これは最初から実行されます。

そして、aTimerに値を割り当てます。

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

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