Timer.AutoReset 属性

定义

命名空间:

System.Timers

程序集:

System.ComponentModel.TypeConverter.dll

Source:

Timer.cs

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; }

member this.AutoReset : bool with get, set

Public Property AutoReset As Boolean

属性值

Boolean

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。

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 AutoReset 为 false， Start 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 true后 Enabled 13 秒首次引发事件。

另请参阅

• Interval
• Enabled
• Start()
• Elapsed