Timer.Interval Propriedade

Definição

Obtém ou define o intervalo, expresso em milissegundos, a partir do qual se eleva o Elapsed evento.

public:
 property double Interval { double get(); void set(double value); };
[System.Timers.TimersDescription("TimerInterval")]
public double Interval { get; set; }
[System.Timers.TimersDescription("TimerInterval")]
[System.ComponentModel.SettingsBindable(true)]
public double Interval { get; set; }
[<System.Timers.TimersDescription("TimerInterval")>]
member this.Interval : double with get, set
[<System.Timers.TimersDescription("TimerInterval")>]
[<System.ComponentModel.SettingsBindable(true)>]
member this.Interval : double with get, set
Public Property Interval As Double

Valor de Propriedade

O tempo, em milissegundos, entre Elapsed eventos. O valor deve ser maior que zero, e menor ou igual a Int32.MaxValue. O padrão é 100 milissegundos.

Atributos

Exceções

O intervalo é menor ou igual a zero.

-ou-

O intervalo é superior ao Int32.MaxValue, e o temporizador está atualmente ativado. (Se o temporizador não estiver atualmente ativado, não é lançada nenhuma exceção até que fique ativado.)

Exemplos

O exemplo seguinte instancia um Timer objeto que dispara o seu Timer.Elapsed evento a cada dois segundos (2000 milissegundos), cria um manipulador de eventos para o evento e inicia o temporizador. O gestor de eventos mostra o valor da ElapsedEventArgs.SignalTime propriedade cada vez que esta é elevada.

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

Observações

Usas a Interval propriedade para determinar a frequência com que o Elapsed evento é disparado. Como a Timer classe depende do relógio do sistema, tem a mesma resolução que o relógio do sistema. Isto significa que o Elapsed evento irá disparar num intervalo definido pela resolução do relógio do sistema se a Interval propriedade for inferior à resolução do relógio do sistema. O exemplo seguinte define a Interval propriedade para 5 milissegundos. Quando executado num sistema Windows cujo relógio do sistema tem uma resolução de aproximadamente 15 milissegundos, o evento é ativado aproximadamente a cada 15 milissegundos em vez de a cada 5 milissegundos.

Note

O relógio do sistema utilizado é o mesmo que o GetTickCount, que não é afetado por alterações feitas com timeBeginPeriod e 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)

Se a sua aplicação exigir maior resolução do que a oferecida pela Timer turma ou pelo relógio do sistema, use os temporizadores multimédia de alta resolução; veja Como: Usar o Temporizador High-Resolution.

Se o intervalo for definido depois de ter Timer começado, a contagem é reiniciada. Por exemplo, se definir o intervalo para 5 segundos e depois definir a Enabled propriedade para true, a contagem começa no momento Enabled em que é definido. Se reiniciar o intervalo para 10 segundos quando a contagem é de 3 segundos, o Elapsed evento é elevado pela primeira vez 13 segundos depois Enabled de ter sido definido para true.

Se Enabled for definido como true e AutoReset for definido como false, o Timer evento aumenta Elapsed apenas uma vez, na primeira vez que o intervalo decorre. Enabled é então definido para false.

Note

Se Enabled e AutoReset estiverem ambos definidos como false, e o temporizador tiver sido previamente ativado, definir a Interval propriedade faz com que o Elapsed evento seja levantado uma vez, como se a Enabled propriedade tivesse sido definida para true. Para definir o intervalo sem aumentar o evento, pode temporariamente definir a Enabled propriedade para true, definir a Interval propriedade para o intervalo de tempo desejado, e depois imediatamente voltar a definir Enabled a propriedade para false.

Aplica-se a

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