Timer.AutoReset 属性

定义

获取或设置一个布尔值,该值指示 Timer 是否应只引发一次 Elapsed 事件((false) 或重复 (true))。

public:
 property bool AutoReset { bool get(); void set(bool value); };
public bool AutoReset { get; set; }
[System.Timers.TimersDescription("TimerAutoReset")]
public bool AutoReset { get; set; }
member this.AutoReset : bool with get, set
[<System.Timers.TimersDescription("TimerAutoReset")>]
member this.AutoReset : bool with get, set
Public Property AutoReset As Boolean

属性值

如果 Timer 应在每次间隔结束时引发 Elapsed 事件,则为 true;如果它仅在间隔第一次结束后引发一次 Elapsed 事件,则为 false。 默认值为 true

属性

示例

以下示例创建一个 Timer ,其 Elapsed 事件在 1.5 秒后触发。 然后,其事件处理程序在主机上显示“Hello World!”

#using <system.dll>

using namespace System;
using namespace System::Timers;

public ref class Timer2
{
private: 
   static System::Timers::Timer^ aTimer;

public:
   static void Main()
   {
      // Create a new Timer with Interval set to 1.5 seconds.
      double interval = 1500.0;
      aTimer = gcnew System::Timers::Timer(interval);

      // Hook up the event handler for the Elapsed event.
      aTimer->Elapsed += gcnew ElapsedEventHandler( OnTimedEvent );
      
      // Only raise the event the first time Interval elapses.
      aTimer->AutoReset = false;
      aTimer->Enabled = true;

      // Ensure the event fires before the exit message appears.
      System::Threading::Thread::Sleep((int) interval * 2);
      Console::WriteLine("Press the Enter key to exit the program.");
      Console::ReadLine();

      // If the timer is declared in a long-running method, use
      // KeepAlive to prevent garbage collection from occurring
      // before the method ends.
      //GC::KeepAlive(aTimer);
   }

private:
   // Handle the Elapsed event.
   static void OnTimedEvent( Object^ /*source*/, ElapsedEventArgs^ /*e*/ )
   {
      Console::WriteLine( "Hello World!" );
   }

};

int main()
{
   Timer2::Main();
}
// The example displays the following output:
//       Hello World!
//       Press the Enter key to exit the program.
using System;
using System.Timers;

public class Example
{
    private static Timer aTimer;

    public static void Main()
    {
        // Create a timer with a 1.5 second interval.
        double interval = 1500.0;
        aTimer = new System.Timers.Timer(interval);

        // Hook up the event handler for the Elapsed event.
        aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);

        // Only raise the event the first time Interval elapses.
        aTimer.AutoReset = false;
        aTimer.Enabled = true;

        // Ensure the event fires before the exit message appears.
        System.Threading.Thread.Sleep((int) interval * 2);
        Console.WriteLine("Press the Enter key to exit the program.");
        Console.ReadLine();
    }

    // Handle the Elapsed event.
    private static void OnTimedEvent(object source, ElapsedEventArgs e)
    {
        Console.WriteLine("Hello World!");
    }
}
// This example displays the following output:
//       Hello World!
//       Press the Enter key to exit the program.
open System.Threading
open System.Timers

// Handle the Elapsed event.
let onTimedEvent source e =
    printfn "Hello World!"

// Create a timer with a 1.5 second interval.
let interval = 1500.
let aTimer = new Timer(interval)

// Hook up the event handler for the Elapsed event.
aTimer.Elapsed.AddHandler(ElapsedEventHandler onTimedEvent)

// Only raise the event the first time Interval elapses.
aTimer.AutoReset <- false
aTimer.Enabled <- true

// Ensure the event fires before the exit message appears.
Thread.Sleep(interval * 2. |> int)
printfn "Press the Enter key to exit the program."
stdin.ReadLine() |> ignore

// This example displays the following output:
//       Hello World!
//       Press the Enter key to exit the program.
Imports System.Timers

Public Module Example
    Private aTimer As System.Timers.Timer

    Public Sub Main()
        ' Create a timer with a 1.5 second interval.
        Dim interval As Double = 1500.0
        aTimer = New System.Timers.Timer(interval)

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

        ' Only raise the event the first time Interval elapses.
        aTimer.AutoReset = False
        aTimer.Enabled = True
        
        
        ' Ensure the event fires before the exit message appears.
        System.Threading.Thread.Sleep(CInt(interval * 2))
        Console.WriteLine("Press the Enter key to exit the program.")
        Console.ReadLine()

        ' If the timer is declared in a long-running method, use
        ' KeepAlive to prevent garbage collection from occurring
        ' before the method ends.
        'GC.KeepAlive(aTimer)
    End Sub

    ' Specify what you want to happen when the Elapsed event is 
    ' raised.
    Private Sub OnTimedEvent(source As Object, e As ElapsedEventArgs)
        Console.WriteLine("Hello World!")
    End Sub
End Module
' This example displays the following output:
'       Hello World!
'       Press the Enter key to exit the program.

注解

如果 AutoResetfalseStart 则必须调用 方法才能再次启动计数。

重置间隔会影响 Elapsed 何时引发事件。 例如,如果将间隔设置为 5 秒,然后将 属性设置为 Enabledtrue,则在设置时 Enabled 开始计数。 如果在计数为 3 秒时将间隔重置为 10 秒,则会Elapsed在 属性设置为 trueEnabled 13 秒首次引发事件。

适用于

另请参阅