Timer.Interval Vlastnost

Definice

Obor názvů:

System.Timers

Sestavení:

netstandard.dll, System.ComponentModel.TypeConverter.dll

Zdroj:

Timer.cs

Získá nebo nastaví interval vyjádřený v milisekundách, při kterém má Elapsed vyvolat událost.

public:
 property double Interval { double get(); void set(double value); };

public double Interval { get; set; }

member this.Interval : double with get, set

Public Property Interval As Double

Hodnota vlastnosti

Double

Čas mezi Elapsed událostmi v milisekundách. Hodnota musí být větší než nula a musí být menší nebo rovna hodnotě Int32.MaxValue. Výchozí hodnota je 100 milisekund.

Výjimky

ArgumentException

Interval je menší nebo roven nule.

nebo

Interval je větší než Int32.MaxValue a časovač je aktuálně povolený. (Pokud časovač není aktuálně povolený, nevyvolá se žádná výjimka, dokud se nepovolí.)

Příklady

Následující příklad vytvoří instanci objektu Timer , který aktivuje událost Timer.Elapsed každých dva sekundy (2000 milisekund), nastaví obslužnou rutinu události pro událost a spustí časovač. Obslužná rutina události zobrazí hodnotu ElapsedEventArgs.SignalTime vlastnosti při každém vyvolání.

using System;
using System.Timers;

public class Example
{
    private static Timer aTimer;

    public static void Main()
    {
        // Create a timer and set a two second interval.
        aTimer = new System.Timers.Timer();
        aTimer.Interval = 2000;

        // Hook up the Elapsed event for the timer. 
        aTimer.Elapsed += OnTimedEvent;

        // Have the timer fire repeated events (true is the default)
        aTimer.AutoReset = true;

        // Start the timer
        aTimer.Enabled = true;

        Console.WriteLine("Press the Enter key to exit the program at any time... ");
        Console.ReadLine();
    }

    private static void OnTimedEvent(Object source, System.Timers.ElapsedEventArgs e)
    {
        Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime);
    }
}
// The example displays output like the following: 
//       Press the Enter key to exit the program at any time... 
//       The Elapsed event was raised at 5/20/2015 8:48:58 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:00 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:02 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:04 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:06 PM

open System.Timers

let onTimedEvent source (e: ElapsedEventArgs) =
    printfn $"The Elapsed event was raised at {e.SignalTime}"

// Create a timer and set a two second interval.
let aTimer = new Timer()
aTimer.Interval <- 2000

// Hook up the Elapsed event for the timer. 
aTimer.Elapsed.AddHandler onTimedEvent

// Have the timer fire repeated events (true is the default)
aTimer.AutoReset <- true

// Start the timer
aTimer.Enabled <- true

printfn "Press the Enter key to exit the program at any time... "
stdin.ReadLine() |> ignore

// The example displays output like the following: 
//       Press the Enter key to exit the program at any time... 
//       The Elapsed event was raised at 5/20/2015 8:48:58 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:00 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:02 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:04 PM 
//       The Elapsed event was raised at 5/20/2015 8:49:06 PM

Imports System.Timers

Public Module Example
    Private aTimer As Timer

    Public Sub Main()
        ' Create a timer and set a two second interval.
        aTimer = New System.Timers.Timer()
        aTimer.Interval = 2000

        ' Hook up the Elapsed event for the timer.  
        AddHandler aTimer.Elapsed, AddressOf OnTimedEvent

        ' Have the timer fire repeated events (true is the default)
        aTimer.AutoReset = True

        ' Start the timer
        aTimer.Enabled = True

        Console.WriteLine("Press the Enter key to exit the program at any time... ")
        Console.ReadLine()
    End Sub

    Private Sub OnTimedEvent(source As Object, e As System.Timers.ElapsedEventArgs)
        Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime)
    End Sub
End Module
' The example displays output like the following: 
'       Press the Enter key to exit the program at any time... 
'       The Elapsed event was raised at 5/20/2015 8:48:58 PM 
'       The Elapsed event was raised at 5/20/2015 8:49:00 PM 
'       The Elapsed event was raised at 5/20/2015 8:49:02 PM 
'       The Elapsed event was raised at 5/20/2015 8:49:04 PM 
'       The Elapsed event was raised at 5/20/2015 8:49:06 PM

Poznámky

Pomocí Interval vlastnosti určíte frekvenci, při které Elapsed se událost aktivuje. Vzhledem k tomu, že Timer třída závisí na systémových hodinách, má stejné rozlišení jako systémové hodiny. To znamená, že Elapsed událost se aktivuje v intervalu definovaném rozlišením systémových hodin, pokud Interval je vlastnost menší než rozlišení systémových hodin. Následující příklad nastaví Interval vlastnost na 5 milisekund. Při spuštění v systému Windows, jehož systémové hodiny mají rozlišení přibližně 15 milisekund, událost se aktivuje přibližně každých 15 milisekund místo každých 5 milisekund.

Poznámka:

Systémové hodiny, které se používají, jsou stejné hodiny, které používá GetTickCount, což nejsou ovlivněny změnami provedenými v timeBeginPeriod a timeEndPeriod.

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)

open System
open System.IO
open System.Timers

let aTimer = new Timer 5
let eventlog = ResizeArray()
let mutable nEventsFired = 0
let mutable previousTime = DateTime()
       
let onTimedEvent source (e: ElapsedEventArgs) =
    String.Format("Elapsed event at {0:HH':'mm':'ss.ffffff} ({1})", e.SignalTime, if nEventsFired = 0 then 0. else (e.SignalTime - previousTime).TotalMilliseconds)
    |> eventlog.Add
    nEventsFired <- nEventsFired + 1

    previousTime <- e.SignalTime

    if nEventsFired = 20 then
        printfn "No more events will fire..."
        aTimer.Enabled <- false

[<EntryPoint>]
let main _ =
    use sr = new StreamWriter(@".\Interval.txt")
    // Create a timer with a five millisecond interval.
    aTimer.Elapsed.AddHandler onTimedEvent
    // Hook up the Elapsed event for the timer. 
    aTimer.AutoReset <- true
    sr.WriteLine $"The timer should fire every {aTimer.Interval} milliseconds."
    aTimer.Enabled <- true

    printfn "Press the Enter key to exit the program... "
    stdin.ReadLine() |> ignore
    for item in eventlog do
        sr.WriteLine item
    printfn "Terminating the application..."
    0

// 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)

Imports System.Collections.Generic
Imports System.IO
Imports System.Timers

Module Example
   Private WithEvents aTimer As Timer
   Private eventlog As List(Of String)
   Private nEventsFired As Integer = 0
   Private previousTime As Date

   Public Sub Main()
        eventlog = New List(Of String)()
        
        Dim sr As New StreamWriter(".\Interval.txt")
        ' Create a timer with a five millisecond interval.
        aTimer = New Timer(5)
        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()
        For Each item In eventlog
           sr.WriteLine(item)
        Next
        sr.Close()
        Console.WriteLine("Terminating the application...")
   End Sub

    Private Sub OnTimedEvent(source As Object, e As ElapsedEventArgs) _
                             Handles aTimer.Elapsed
        eventlog.Add(String.Format("Elapsed event at {0:HH':'mm':'ss.ffffff} ({1})", 
                                   e.SignalTime, 
                                   If(nEventsFired = 0, 
                                      0.0, (e.SignalTime - previousTime).TotalMilliseconds)))
        nEventsFired += 1
        previousTime = e.SignalTime
        if nEventsFired = 20 Then
           Console.WriteLine("No more events will fire...")
           aTimer.Enabled = False
        End If
   End Sub
End Module
' The example displays the following output:
'       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)

Pokud vaše aplikace vyžaduje vyšší rozlišení, než jaké nabízí Timer třída nebo systémové hodiny, použijte multimediální časovače s vysokým rozlišením; viz Postupy: Použití High-Resolution časovače.

Pokud je interval nastavený po Timer spuštění, počet se resetuje. Pokud například nastavíte interval na 5 sekund a nastavíte Enabled vlastnost na truehodnotu , počet začíná v čase Enabled . Pokud interval resetujete na 10 sekund, pokud je počet 3 sekundy, Elapsed událost se vyvolá poprvé 13 sekund po Enabled nastavení .true

Pokud Enabled je nastavena na hodnotu a AutoReset je nastavena truefalsena , Timer vyvolá Elapsed událost pouze jednou, při prvním uplynutí intervalu. Enabled je pak nastavena na falsehodnotu .

Poznámka:

Pokud Enabled a AutoReset jsou oba nastaveny na falsea časovač byl dříve povolen, nastavení Interval vlastnosti způsobí Elapsed , že událost bude vyvolána jednou, jako by Enabled vlastnost byla nastavena na true. Chcete-li nastavit interval bez vyvolání události, můžete dočasně nastavit vlastnost na true, nastavit Interval vlastnost na požadovaný časový interval a pak okamžitě nastavit Enabled vlastnost zpět na false.Enabled

Viz také

• AutoReset
• Enabled
• Elapsed