Timer.Interval Vlastnost

Definice

Obor názvů:

System.Timers

Sestavení:

System.ComponentModel.TypeConverter.dll

Zdroj:

Timer.cs

Získá nebo nastaví interval vyjádřený v milisekundách, ve kterém se má vyvolat Elapsed 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 menší nebo rovna Hodnotě Int32.MaxValue. Výchozí hodnota je 100 milisekund.

Výjimky

ArgumentException

Interval je menší než 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 svou Timer.Elapsed událost každé dvě sekundy (2000 milisekund), nastaví obslužnou rutinu události pro událost a spustí časovač. Obslužná rutina události zobrazí hodnotu ElapsedEventArgs.SignalTime vlastnosti při každém jejím vyvolání.

using namespace System;
using namespace System::Timers;

public ref class Example
{
private:
    static System::Timers::Timer^ aTimer;

public:
    static void Demo()
    {
        // Create a timer and set a two second interval.
        aTimer = gcnew System::Timers::Timer();
        aTimer->Interval = 2000;

        // Hook up the Elapsed event for the timer. 
        aTimer->Elapsed += gcnew System::Timers::ElapsedEventHandler(Example::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);
    }
};

int main()
{
    Example::Demo();
}
// 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

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

Vlastnost slouží Interval k určení frekvence, s jakou Elapsed se událost aktivuje. Vzhledem k tomu, že Timer třída závisí na systémových hodinách, má stejné rozlišení jako systémové hodiny. To znamená, že událost Elapsed 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 jako GetTickCount, které nejsou ovlivněny změnami 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 časovače multimédií s vysokým rozlišením. Viz Postup: Použití časovače High-Resolution.

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

Pokud Enabled je nastavena na true a AutoReset je nastavena na false, Timer vyvolá Elapsed událost pouze jednou, při prvním uplynutí intervalu. Enabled se pak nastaví na false.

Poznámka

AutoReset Pokud Enabled jsou obě hodnoty nastavené na falsea časovač byl dříve povolen, nastavení Interval vlastnosti způsobíElapsed, že se událost vyvolá jednou, jako kdyby Enabled byla vlastnost nastavená na truehodnotu . Pokud chcete 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